ON24 (ONTF) 10-Q 10 Nov 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 04, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Quarterly Report	true
Document Transition Report	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Registrant Name	ON24, INC.
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Trading Symbol	ONTF
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Security Exchange Name	NYSE
Entity Common Stock, Shares Outstanding		47,567,984
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Incorporation, State or Country Code	DE
Entity File Number	001-39965
Entity Tax Identification Number	94-3292599
Entity Address, Address Line One	50 Beale Street, 8th Floor
Entity Address, City or Town	San Francisco
Entity Address, Postal Zip Code	94105
City Area Code	415
Local Phone Number	369-8000
Entity Address, State or Province	CA
Entity Central Index Key	0001110611
Document Period End Date	Sep. 30, 2021

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 197,788	$ 58,243
Marketable investments	201,896	3,000
Accounts receivable, net of allowances and reserves of $2,347 and $2,173 as of September 30, 2021 and December 31, 2020, respectively	36,798	48,617
Deferred contract acquisition costs, current	11,718	10,528
Prepaid expenses and other current assets	9,661	7,079
Total current assets	457,861	127,467
Property and equipment, net	8,849	9,051
Deferred contract acquisition costs, non-current	20,205	18,753
Other long-term assets	995	1,447
Total assets	487,910	156,718
Current liabilities
Accounts payable	2,026	4,730
Accrued liabilities	22,989	17,439
Deferred revenue	91,185	92,240
Long-term debt, current portion	2,128	2,359
Total current liabilities	118,328	116,768
Long-term debt	2,543	25,727
Other long-term liabilities	3,374	4,022
Total liabilities	124,245	146,517
Commitments and contingencies
Stockholders’ equity (deficit)
Common stock, $0.0001 par value per share; 500,000,000 and 50,000,000 shares authorized as of September 30, 2021 and December 31, 2020, respectively; 47,425,423 and 10,896,137 shares issued and outstanding as of September 30, 2021 and December 31, 2020, respectively	5	1
Additional paid-in capital	549,455	27,512
Accumulated deficit	(186,010)	(171,263)
Accumulated other comprehensive income	215	94
Total stockholders’ equity (deficit)	363,665	(143,656)
Total liabilities, convertible preferred stock and stockholders’ equity (deficit)	487,910	156,718
Convertible Class A-1 and Class A-2 Preferred Stock
Temporary Equity
Convertible preferred stock	0	83,857
Redeemable Convertible Class B and Class B-1 Preferred Stock
Temporary Equity
Convertible preferred stock	$ 0	$ 70,000

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Accounts receivable, allowances and reserves	$ 2,347	$ 2,173
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, authorized (in shares)	500,000,000	50,000,000
Common stock, issued (in shares)	47,425,423	10,896,137
Common stock, outstanding (in shares)	47,425,423	10,896,137
Convertible Class A-1 and Class A-2 Preferred Stock
Convertible preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Convertible preferred stock, authorized (in shares)	0	21,699,945
Convertible preferred stock, issued (in shares)	0	21,683,548
Convertible preferred stock outstanding (in shares)	0	21,683,548
Convertible preferred stock, liquidation preference	$ 0	$ 102,776
Redeemable Convertible Class B and Class B-1 Preferred Stock
Convertible preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Convertible preferred stock, authorized (in shares)	0	5,543,918
Convertible preferred stock, issued (in shares)	0	5,543,918
Convertible preferred stock outstanding (in shares)	0	5,543,918
Convertible preferred stock, liquidation preference	$ 0	$ 70,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Revenue:
Total revenue	$ 49,362	$ 42,589	$ 151,579	$ 103,655
Cost of revenue:
Total cost of revenue	12,067	8,620	34,634	23,288
Gross profit	37,295	33,969	116,945	80,367
Operating expenses:
Sales and marketing	26,591	15,756	75,981	40,495
Research and development	9,114	4,660	25,222	13,272
General and administrative	10,851	6,712	29,719	14,370
Total operating expenses	46,556	27,128	130,922	68,137
Income (loss) from operations	(9,261)	6,841	(13,977)	12,230
Interest expense	65	228	402	633
Other (income) expense, net	106	(23)	433	226
Income (loss) before provision for (benefit from) income taxes	(9,432)	6,636	(14,812)	11,371
Provision for (benefit from) income taxes	(32)	31	(65)	123
Net income (loss)	(9,400)	6,605	(14,747)	11,248
Cumulative preferred dividends allocated to preferred stockholders	0	(1,467)	(558)	(4,219)
Net income (loss) attributable to common stockholders	$ (9,400)	$ 5,138	$ (15,305)	$ 7,029
Net income (loss) per share attributable to common stockholders:
Basic (in dollars per share)	$ (0.20)	$ 0.14	$ (0.36)	$ 0.19
Diluted (in dollars per share)	$ (0.20)	$ 0.12	$ (0.36)	$ 0.17
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders:
Basic (in shares)	47,101,200	10,420,584	42,149,108	9,755,373
Diluted (in shares)	47,101,200	17,068,097	42,149,108	13,417,405
Subscription and other platform
Revenue:
Total revenue	$ 43,601	$ 34,356	$ 130,888	$ 81,379
Cost of revenue:
Total cost of revenue	8,718	5,425	24,382	14,405
Professional services
Revenue:
Total revenue	5,761	8,233	20,691	22,276
Cost of revenue:
Total cost of revenue	$ 3,349	$ 3,195	$ 10,252	$ 8,883

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (9,400)	$ 6,605	$ (14,747)	$ 11,248
Other comprehensive income (loss)
Foreign currency translation adjustment, net of tax	46	134	154	188
Unrealized loss on available for sale debt securities, net of tax	(15)	0	(33)	0
Total other comprehensive income	31	134	121	188
Total comprehensive income (loss)	$ (9,369)	$ 6,739	$ (14,626)	$ 11,436

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Convertible Preferred Stock	Redeemable Convertible Preferred Stock
Beginning balance, shares at Dec. 31, 2019						21,683,548	5,543,918
Beginning balance at Dec. 31, 2019						$ 83,857	$ 70,000
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of convertible preferred stock and redeemable convertible preferred stock to common stock upon initial public offering	$ 0
Ending balance, shares at Sep. 30, 2020						21,683,548	5,543,918
Ending balance at Sep. 30, 2020						$ 83,857	$ 70,000
Beginning balance, shares at Dec. 31, 2019		8,953,967
Beginning balance at Dec. 31, 2019	(171,208)	$ 1	$ 20,809	$ (192,016)	$ (2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		1,788,174
Issuance of common stock upon exercise of stock options	3,337	$ 0	3,337
Stock-based compensation expense	1,453		1,453
Other comprehensive income	188				188
Net income (loss)	11,248			11,248
Ending balance, shares at Sep. 30, 2020		10,742,141
Ending balance at Sep. 30, 2020	(154,982)	$ 1	25,599	(180,768)	186
Beginning balance, shares at Jun. 30, 2020						21,683,548	5,543,918
Beginning balance at Jun. 30, 2020						$ 83,857	$ 70,000
Ending balance, shares at Sep. 30, 2020						21,683,548	5,543,918
Ending balance at Sep. 30, 2020						$ 83,857	$ 70,000
Beginning balance, shares at Jun. 30, 2020		10,187,478
Beginning balance at Jun. 30, 2020	(163,439)	$ 1	23,881	(187,373)	52
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		554,663
Issuance of common stock upon exercise of stock options	1,098	$ 0	1,098
Stock-based compensation expense	620		620
Other comprehensive income	134				134
Net income (loss)	6,605			6,605
Ending balance, shares at Sep. 30, 2020		10,742,141
Ending balance at Sep. 30, 2020	(154,982)	$ 1	25,599	(180,768)	186
Beginning balance, shares at Dec. 31, 2020						21,683,548	5,543,918
Beginning balance at Dec. 31, 2020						$ 83,857	$ 70,000
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of convertible preferred stock and redeemable convertible preferred stock to common stock upon initial public offering (in shares)						(21,683,548)	(5,543,918)
Conversion of convertible preferred stock and redeemable convertible preferred stock to common stock upon initial public offering	$ (153,857)					$ (83,857)	$ (70,000)
Ending balance, shares at Sep. 30, 2021						0	0
Ending balance at Sep. 30, 2021						$ 0	$ 0
Beginning balance, shares at Dec. 31, 2020	10,896,137	10,896,137
Beginning balance at Dec. 31, 2020	$ (143,656)	$ 1	27,512	(171,263)	94
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)	1,728,321	1,688,274
Issuance of common stock upon exercise of stock options	$ 4,282	$ 0	4,282
Issuance of common stock upon release of restricted stock units (in shares)		13,618
Issuance of common stock upon release of restricted stock units	0	$ 0	0
Conversion of convertible preferred stock and redeemable convertible preferred stock to common stock upon initial public offering (in shares)		27,227,466
Conversion of convertible preferred stock and redeemable convertible preferred stock to common stock upon initial public offering	153,857	$ 3	153,854
Issuance of common stock upon initial public offering, net of underwriting discounts and other offering costs (in shares)		7,599,928
Issuance of common stock upon initial public offering, net of underwriting discounts and other offering costs	348,014	$ 1	348,013
Payment for employee tax withheld upon exercising stock options	(2,001)		(2,001)
Stock-based compensation expense	17,795		17,795
Other comprehensive income	121				121
Net income (loss)	$ (14,747)			(14,747)
Ending balance, shares at Sep. 30, 2021	47,425,423	47,425,423
Ending balance at Sep. 30, 2021	$ 363,665	$ 5	549,455	(186,010)	215
Beginning balance, shares at Jun. 30, 2021						0	0
Beginning balance at Jun. 30, 2021						$ 0	$ 0
Ending balance, shares at Sep. 30, 2021						0	0
Ending balance at Sep. 30, 2021						$ 0	$ 0
Beginning balance, shares at Jun. 30, 2021		46,449,556
Beginning balance at Jun. 30, 2021	362,716	$ 5	539,137	(176,610)	184
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		962,249
Issuance of common stock upon exercise of stock options	2,487	$ 0	2,487
Issuance of common stock upon release of restricted stock units (in shares)		13,618
Issuance of common stock upon release of restricted stock units	0	$ 0	0
Stock-based compensation expense	7,831		7,831
Other comprehensive income	31				31
Net income (loss)	$ (9,400)			(9,400)
Ending balance, shares at Sep. 30, 2021	47,425,423	47,425,423
Ending balance at Sep. 30, 2021	$ 363,665	$ 5	$ 549,455	$ (186,010)	$ 215

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net income (loss)	$ (14,747)	$ 11,248
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	3,423	1,930
Stock-based compensation expense	17,795	1,453
Amortization of deferred contract acquisition cost	11,305	7,460
Provision for allowance for doubtful accounts and billing reserve	1,276	1,449
Other	191	0
Changes in operating assets and liabilities:
Accounts receivable	10,543	(21,424)
Deferred contract acquisition cost	(13,947)	(19,280)
Prepaid expenses and other assets	(5,358)	(2,539)
Accounts payable	(2,219)	1,116
Accrued liabilities	3,122	2,709
Deferred revenue	(1,055)	42,754
Other long-term liabilities	(648)	(37)
Net cash provided by operating activities	9,681	26,839
Cash flows from investing activities:
Purchase of property and equipment	(2,440)	(674)
Purchase of marketable securities	(207,039)	(5,000)
Proceeds from maturities and paydowns of marketable securities	11,401	5,000
Net cash used in investing activities	(198,078)	(674)
Cash flows from financing activities:
Proceeds from initial public offering, net of underwriting discounts	353,397	0
Proceeds from issuance of common stock resulting from exercise of stock options	4,282	3,337
Payment of tax withholding obligations related to net share settlements of stock options exercise	(2,001)	0
Proceeds from long-term debt	0	18,165
Repayments of long-term debt	(22,532)	(18,129)
Repayment of capital lease obligations	(1,885)	(826)
Payments of offering costs	(3,481)	0
Net cash provided by financing activities	327,780	2,547
Effect of exchange rate changes on cash, cash equivalents and restricted cash	154	188
Net increase in cash, cash equivalents and restricted cash	139,537	28,900
Cash, cash equivalents and restricted cash, beginning of period	58,345	18,933
Cash, cash equivalents and restricted cash, end of period	197,882	47,833
Supplemental disclosures of cash flow information:
Cash paid for taxes, net of refunds	359	172
Cash paid for interest	489	724
Supplemental disclosures of noncash investing and financing activities:
Equipment acquired under capital leases	1,586	3,180
Equipment purchased funded by liabilities	391	179
Property and equipment purchased not yet paid	29	692
Marketable securities purchased not yet settled	3,482	0
Conversion of convertible preferred stock and redeemable convertible preferred stock to common stock	153,857	0
Cash and cash equivalents	197,788	47,739
Restricted cash included in other assets, non-current	94	94
Total cash, cash equivalent, and restricted cash	$ 197,882	$ 47,833

Description of Business and Sig

Description of Business and Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Significant Accounting Policies	Description of Business and Significant Accounting Policies Description of Business ON24, Inc. and its subsidiaries (together, ON24 or the Company) provides a leading, cloud-based digital experience platform that enables businesses to convert customer engagement into revenue through interactive webinar experiences, virtual event experiences and multimedia content experiences. The Company’s platform offers a portfolio of interactive, personalized and content-rich digital experience products that creates and captures actionable, real-time data at scale from millions of professionals every month to provide businesses with buying signals and behavioral insights to efficiently convert prospects into customers. The Company was incorporated in the state of Delaware in January 1998 as NewsDirect, Inc. and in December 1998 changed its name to ON24, Inc. The Company is headquartered in San Francisco, California. Initial Public Offering On February 5, 2021, the Company closed its initial public offering (IPO) of 7,599,928 shares of its common stock at a public offering price of $50 per share for net proceeds of approximately $348.0 million, after deducting the underwriting discount of approximately $26.6 million and other offering costs of approximately $5.4 million. The shares of common stock sold in the IPO and the net proceeds from the IPO included the full exercise of the underwriters’ option to purchase additional shares. Upon the closing of the IPO, all of the Company's outstanding shares of Class A-1 and Class A-2 convertible preferred stock and Class B and Class B-1 redeemable convertible preferred stock were automatically converted into an aggregate of 27,227,466 shares of common stock on a one-for-one basis. Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (U.S. GAAP) and applicable rules and regulations of the Securities and Exchange Commission (SEC) for interim financial reporting. Certain information and note disclosures included in the Company’s annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in the Company’s annual report on Form 10-K for the year ended December 31, 2020. In the opinion of management, the condensed consolidated financial statements reflect all adjustments that are normal and recurring in nature and necessary for fair financial statement presentation. All intercompany transactions and balances have been eliminated in consolidation. The results of operations for the three and nine months ended September 30, 2021 are not necessarily indicative of the operating results anticipated for the full year. Certain prior period amounts have been reclassified on the condensed consolidated statements of cash flows to conform to the current year's presentation. Use of Estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Significant items subject to such estimates and assumptions include, but are not limited to, the estimated expected benefit period for deferred contract acquisition costs, the determination of standalone selling price for the Company’s performance obligations, the allowance for doubtful accounts and billing reserve, the useful lives of long-lived assets, the estimated value of common stock prior to the IPO and other assumptions used to measure stock-based compensation, the valuation of deferred income tax assets and uncertain tax positions. Actual results could differ from those estimates. Significant Accounting Policies Effective January 1, 2021, the Company elected to account for forfeited awards as they occur. Prior to 2021, the Company estimated the number of awards expected to be forfeited at the time of grant and revised its estimates in subsequent periods if the actual forfeitures differed from the estimates. The impact of the change was not material. There has been no material change to the Company’s significant accounting policies during the three and nine months ended September 30, 2021. Deferred Offering Costs Deferred offering costs consist primarily of accounting, legal and other fees incremental and directly related to the Company’s IPO. Upon closing of the IPO on February 5, 2021, the deferred offering costs of $5.4 million were reclassified into stockholders' equity (deficit) and recorded against the proceeds from the offering. Deferred offering costs as of December 31, 2020 was $3.2 million within prepaid expenses and other current assets on the condensed consolidated balance sheets. Stock-Based Compensation Stock-based compensation expense related to stock awards is recognized based on the fair value of the awards granted. The fair value of each option award is estimated on the grant date using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires the input of highly subjective assumptions, including the fair value of the underlying common stock, the risk-free interest rates, the expected term of the option, the expected volatility of the price of the Company’s common stock and the expected dividend yield of the Company’s common stock. The assumptions used to determine the fair value of the option awards represent management’s best estimates. These estimates involve inherent uncertainties and application of management’s judgement. The related stock-based compensation expense is recognized on a straight-line basis over the requisite service period for each separately vesting portion of the award, which is generally four years. Effective January 1, 2021, the Company elected to account for forfeited awards as they occur. Prior to 2021, the Company estimated the number of awards expected to be forfeited at the time of grant and revised its estimates in subsequent periods if the actual forfeitures differed from the estimates. This change in accounting policy did not have a material impact on the Company’s condensed consolidated financial statements. Recently Adopted Accounting Standards In December 2019, the FASB issued ASU No. 2019-12, Income Taxes Topic 740: Simplifying the Accounting for Income Taxes , which removes a variety of exceptions within the framework of ASC 740. These include the exception to the incremental approach for intraperiod tax allocation in the event of a loss from continuing operations and income or a gain from other items (such as other comprehensive income), and the exception to using general methodology for the interim period tax accounting for year-to-date losses that exceed anticipated losses. For public business entities, ASU No. 2019-12 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. For all other entities, ASU No. 2019-12 is effective for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022. Early adoption of the amendments is permitted, including adoption in any interim period for (1) public business entities for periods for which financial statements have not yet been issued and (2) all other entities for periods for which financial statements have not yet been made available for issuance. The adoption of this standard did not have a material impact on its condensed consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract . This new standard requires an entity (customer) in a hosting arrangement that is a service contract to follow the guidance in Subtopic 350-40 to determine which implementation costs to capitalize as an asset related to the service contract and which costs to expense. Costs for implementation activities in the application development stage can be capitalized depending on the nature of the costs, while costs incurred during the preliminary project and post-implementation stages are expensed as the activities are performed. The costs capitalized are expensed over the term of the hosting arrangement. The amendments in ASU No. 2018-15 also require the entity to present the expense related to the capitalized implementation costs in the same line item in the statement of income as the fees associated with the hosting element (service) of the arrangement and classify payments for capitalized implementation costs in the statement of cash flows in the same manner as payments made for fees associated with the hosting element. ASU No. 2018-15 is effective for public business entities for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. For all other entities, ASU No. 2018-15 is effective for annual reporting periods beginning after December 15, 2020, and interim periods within annual periods beginning after December 15, 2021. ASU No. 2018-15 should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. The Company adopted ASU No. 2018-15 effective January 1, 2021 using a prospective approach. The adoption of this standard did not have a material impact on its condensed consolidated financial statements.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Disaggregation of Revenue The following table depicts the disaggregation of revenue by geographic region based on the shipping address of customers (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 United States $ 36,922 $ 32,510 $ 112,212 $ 80,015 EMEA 8,524 6,981 27,382 16,807 Other 3,916 3,098 11,985 6,833 Total revenue $ 49,362 $ 42,589 $ 151,579 $ 103,655 The following table summarizes the foreign countries which contributed 10% or more of the total revenue (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 United Kingdom * * 11 % * * Represent less than 10% of total revenue No single customer accounted for 10% or more of the total revenue during the three and nine months ended September 30, 2021 and 2020. Additionally, no single customer accounted for 10% or more of accounts receivable as of September 30, 2021 and December 31, 2020. The following table summarizes revenue by digital experience platform and Legacy offering (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Digital experience platform - subscription and other platform $ 43,564 $ 34,297 $ 130,789 $ 80,010 Digital experience platform - professional services 5,761 8,183 20,666 21,705 Legacy - subscription and other platform 37 59 99 1,369 Legacy - professional services — 50 25 571 Total revenue $ 49,362 $ 42,589 $ 151,579 $ 103,655 Contract Balances Accounts receivable : The Company records accounts receivable when the Company has a contractual right to consideration. In some arrangements, a right to consideration for the Company’s performance under the customer contract may occur before invoicing to the customer, resulting in an unbilled receivable. As of September 30, 2021 and December 31, 2020, unbilled receivables were included within accounts receivable, net of allowance for doubtful accounts on the condensed consolidated balance sheets and were not material . Contract assets: The Company records a contract asset when the Company has satisfied a performance obligation but does not yet have an unconditional right to consideration. Contract assets are included in prepaid expenses and other current assets in the condensed consolidated balance sheets and were not material as of September 30, 2021 and December 31, 2020. Contract liabilities : The Company defers its revenue when the Company has the right to invoice in advance of performance under a customer contract. The current portion of deferred revenue balances is recognized during the following 12-month period and the remaining portion is recorded as noncurrent, which is included in other long-term liabilities on the consolidated balance sheet. The amount of revenue recognized during the three and nine months ended September 30, 2021 that was included in deferred revenue at the beginning of the period was $14.8 million and $80.2 million, respectively. Remaining Performance Obligations The terms of the Company’s subscription agreements are primarily annual and, to a lesser extent, multi-year. The Company may bill for the full term in advance or on an annual, quarterly or monthly basis, depending on the terms of the agreement. As of September 30, 2021, the aggregate amount of the transaction price allocated to remaining performance obligations was $143.8 million, which consists of both billed consideration in the amount of $92.0 million and unbilled consideration in the amount of $51.8 million that the Company expects to recognize as revenue. As of September 30, 2021, the Company expects to recognize 81% of its remaining performance obligations as revenue over the subsequent 12 months and the remainder thereafter. Costs to Obtain a Contract The Company capitalizes sales commissions and associated payroll taxes paid to internal sales personnel and third-party referral fees that are incremental costs resulting from obtaining a contract with a customer. These costs are recorded as deferred contract acquisition costs on the condensed consolidated balance sheets. The Company determines whether costs should be deferred based on its sales compensation plans and if the commissions are incremental and would not have occurred absent the customer contract. Sales commissions paid upon the initial acquisition of a customer contract are amortized over an estimated period of benefit of five years as the Company specifically anticipates renewals of customer contracts and commissions paid on renewal contracts are not commensurate with commissions paid on new customer contracts. Sales commissions paid upon renewal of customer contracts are amortized over the contractual renewal term. Amortization is recognized on a straight-line basis commensurate with the pattern of revenue recognition. Sales commissions paid related to professional services are amortized over the expected service period. The Company determines the period of benefit for commissions paid for the acquisition of the initial customer contract by taking into consideration the initial estimated customer life and the technological life of its platform and related significant features. Amortization of deferred contract acquisition costs was $3.8 million and $11.3 million for the three and nine months ended September 30, 2021, respectively, and $3.2 million and $7.5 million for the three and nine months ended September 30, 2020, respectively. Amortization of deferred contract acquisition costs is included in sales and marketing expense in the condensed consolidated statements of operations. The Company has no impairment losses relating to deferred contract acquisition costs during the periods presented.

Marketable Securities

Marketable Securities	9 Months Ended
	Sep. 30, 2021
Marketable Securities [Abstract]
Marketable Securities	Marketable Securities M arketable securities consisted of the following as of the periods presented (in thousands): September 30, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Marketable Securities U.S. Treasury securities $ 136,386 $ 4 $ (25) $ 136,365 Certificates of deposit 6,495 — — 6,495 Corporate debt securities 39,836 4 (15) 39,825 Commercial papers 8,236 2 — 8,238 Asset-backed securities 10,976 1 (4) 10,973 Total marketable securities $ 201,929 $ 11 $ (44) $ 201,896 December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Marketable Securities Certificates of deposit $ 3,000 $ — $ — $ 3,000 Total marketable securities $ 3,000 $ — $ — $ 3,000 The Company’s marketable securities have been classified as available for sale. All available for sale debt securities are available for use in current operations. Accordingly, they have been classified as current. As of September 30, 2021, the Company had no marketable securities in a continuous loss position for 12 months or more. As of December 31, 2020, the Company had no marketable securities in a loss position. The Company reviews the individual securities that have unrealized losses on a regular basis to evaluate whether any security has experienced other-than-temporary decline in fair value below amortized cost. The Company evaluates, among other factors, whether the Company has the intention to sell any of these marketable securities and whether it is more likely than not that the Company will be required to sell any securities before recovery of the amortized cost basis. Since the Company has the ability to hold its investments until maturity, and the decline in fair value was not due to any credit-related factor, no decline was deemed to be other-than-temporary. The Company had no realized gains or losses from marketable securities that were reclassified out of accumulated other comprehensive income for the three and nine months ended September 30, 2021 and 2020. The following summarizes the remaining contractual maturities of the Company’s marketable securities as of September 30, 2021 : Fair Value One year or less $ 46,601 Over one year through five years 155,295 Total marketable securities $ 201,896

Fair Value Measurement

Fair Value Measurement	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurement	Fair Value Measurement The following tables summarizes our financial instruments recorded at fair value on a recurring basis by level within the fair value hierarchy as of the periods presented September 30, 2021 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 170,768 $ — $ — $ 170,768 Marketable Securities U.S. Treasury securities — 136,365 — 136,365 Certificates of deposit — 6,495 — 6,495 Corporate debt securities — 39,825 — 39,825 Commercial papers — 8,238 — 8,238 Asset-backed securities — 10,973 — 10,973 Total cash equivalents and marketable securities $ 170,768 $ 201,896 $ — $ 372,664 December 31, 2020 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 2,027 $ — $ — $ 2,027 Marketable Securities — Certificates of deposit 3,000 — — 3,000 Total cash equivalents and marketable securities $ 5,027 $ — $ — $ 5,027 As of September 30, 2021, the Company classified its highly liquid money market funds within level 1 of the fair value hierarchy because they are valued based on quoted market prices in active markets. The Company classified its U.S. Treasury securities, certificates of deposit, commercial paper, corporate debt securities and asset-backed securities within level 2 of the fair value hierarchy because they are valued using inputs other than quoted prices that are directly or indirectly observable in the market, including readily available pricing sources for the identical underlying security, which may not be actively traded. As of December 31, 2020, the Company classified its highly liquid money market funds and certificates of deposit within level 1 of the fair value hierarchy because they are valued based on quoted market prices in active markets.

Balance Sheets Components

Balance Sheets Components	9 Months Ended
	Sep. 30, 2021
Balance Sheet Related Disclosures [Abstract]
Balance Sheets Components	Balance Sheets Components Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following as of the periods presented (in thousands): September 30, 2021 December 31, 2020 Deferred offering costs $ — $ 3,220 Prepaid expenses 6,611 2,848 Other receivables 2,460 873 Other 590 138 Prepaid expenses and other current assets $ 9,661 $ 7,079 Property and Equipment, Net Property and equipment, net consisted of the following as of the periods presented (in thousands): September 30, 2021 December 31, 2020 Computer, equipment and software (1) $ 27,315 $ 24,175 Furniture and fixtures 1,116 1,108 Leasehold improvements 3,708 3,708 Property and equipment, gross 32,139 28,991 Less: Accumulated depreciation and amortization (2) (23,290) (19,940) Property and equipment, net $ 8,849 $ 9,051 (1) Includes assets recorded under capital leases of $6.1 million and $6.9 million as of September 30, 2021 and December 31, 2020, respectively. (2) Includes amount for assets recorded under capital leases of $2.4 million and $2.2 million as of September 30, 2021 and December 31, 2020, respectively. Depreciation and amortization expense was $1.1 million and $3.4 million for the three and nine months ended September 30, 2021, respectively, and $0.7 million and $1.9 million for the three and nine months ended September 30, 2020, respectively. The following table presents the property and equipment, net of depreciation and amortization, by geographic region (in thousands): September 30, 2021 December 31, 2020 United States $ 8,556 $ 8,698 EMEA 240 308 Other 53 45 Total property and equipment, net $ 8,849 $ 9,051 Accrued Liabilities Accrued liabilities consisted of the following as of the periods presented (in thousands): September 30, 2021 December 31, 2020 Accrued bonus $ 3,063 $ 2,785 Accrued vacation 3,444 2,724 Accrued commissions 2,022 3,149 Accrued ESPP 2,495 — Sales and other tax liabilities 477 1,086 Accrued liability for unsettled investment trades 3,482 — Other 8,006 7,695 Accrued liabilities $ 22,989 $ 17,439 Other Long-term Liabilities Other long-term liabilities consisted of the following as of the periods presented (in thousands): September 30, 2021 December 31, 2020 Deferred rent liabilities $ 2,118 $ 2,543 Deferred revenue 896 1,152 Other 360 327 Other long-term liabilities $ 3,374 $ 4,022

Debt

Debt	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Debt	Debt Debt consisted of the following as of the periods presented (in thousands): September 30, 2021 December 31, 2020 Revolving line of credit $ — $ 22,350 Equipment loan agreements 643 438 Capital leases 4,028 5,298 Total debt 4,671 28,086 Less: Current portion (2,128) (2,359) Total long-term debt $ 2,543 $ 25,727 Revolving Line of Credit In September 2021, the Company amended its revolving line of credit with a financing institution effective August 2021, which increased the Company's borrowing capacity to a maximum of $50.0 million with a letter of credit sublimit of $4.0 million and a credit card sublimit of $1.0 million. The amendment allows the Company to borrow up to $50.0 million if the Company maintains at least $100.0 million on deposit at the institution. If such deposit is less than $100.0 million, the Company may borrow up to the lesser of $50.0 million or an amount determined by the Company's trailing five months of recurring revenue, annualized renewal rate and annualized monthly churn rate, as defined by the agreement. The terms of the agreement permit voluntary prepayment without premium or penalty. The revolving credit facility matures in August 2024 and is secured by substantially all of the Company’s assets. The outstanding principal balance on the revolving line of credit, if any, is due at maturity. The Company is required to pay quarterly in arrears a commitment fee of 0.15% per annum on the undrawn portion available under the revolving line of credit. As of September 30, 2021, the Company had an outstanding standby letter of credit of $1.2 million as a guarantee for a leased space. Interest on the revolving credit facility is payable monthly in arrears at a rate equal to the lender’s prime referenced rate as defined in the agreement. Prior to this amendment, interest on the revolving line of credit was the prime rate, as published by the Wall Street Journal (Prime Rate), plus 0.75% effective July 31, 2020. The referenced prime rate was 3.25% as of September 30, 2021 and the Prime Rate was 3.25% as of September 30, 2020. The revolving credit facility is subject to certain restrictions and financial covenants, including the requirement of maintaining a minimum debt to EBITDA ratio when the Company’s current portion of the total borrowing exceeds $5.0 million and the Company fails to maintain $100.0 million on deposits. In addition, the revolving line of credit agreement restricts the Company from paying dividends without prior approval from the financing institution. The Company was not subject to the financial covenants as of September 30, 2021. In the first quarter of 2021, the Company repaid in full the then outstanding principal balance of its revolving line of credit of $22.4 million. Equipment Loan Agreements The Company has entered into various equipment loan agreements that allow it to obtain financing to purchase equipment. Borrowings are secured by the equipment purchased. The equipment loan agreements are repaid over a period up to 36 months beginning from the date of the advance at an interest rate ranging from 5.8% to 10.1%. As of September 30, 2021 and December 31, 2020 the Company owed $0.6 million and $0.4 million, respectively, on the equipment loans . Capital Leases The Company has entered into various noncancelable capital lease agreements for its equipment with lease periods expiring between 2021 and 2024. As of September 30, 2021, future payments under the equipment loan agreements and capital lease obligations, are as follows (in thousands): Equipment Loans Capital Leases Total Remainder of 2021 $ 65 $ 432 $ 497 2022 271 2,074 2,345 2023 236 1,671 1,907 2024 71 71 142 Total payments 643 4,248 4,891 Less: Amount representing interest — 220 220 Total payments, net of interest $ 643 $ 4,028 $ 4,671

Commitment and Contingencies

Commitment and Contingencies	9 Months Ended
	Sep. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitment and Contingencies	Commitment and Contingencies Purchase Obligations The Company has non-cancelable purchase commitments of $6.0 million as of September 30, 2021, primarily related to software license fees and co-location facilities and services. Of which $0.7 million is expected to be paid in the fourth quarter of 2021, $3.5 million in 2022, $1.7 million in 2023 and $0.1 million in 2024. Contingencies The Company has agreed to indemnify its directors and executive officers for costs associated with any fees, expenses, judgments, fines, and settlement amounts incurred by any of these persons in any action or proceeding to which any of those persons is, or is threatened to be, made a party by reason of the person’s service as a director or officer, including any action by the Company, arising out of that person’s services as the Company’s director or officer or that person’s services provided to any other company or enterprise at the Company’s request. The Company maintains director and officer insurance coverage that may enable the Company to recover a portion of any future amounts paid. FASB ASC 450-20, Contingencies , sets forth the rules for accounting for uncertain tax positions for taxes not based on income. When a loss contingency exists, the likelihood of the incurrence of the liability can range from probable to remote. The Company believes it is reasonably possible that a loss will result from the sales and use tax assessments in the range of zero to $1.8 million. The Company has not recorded an accrual as of September 30, 2021 and December 31, 2020. Legal Proceedings The Company, its Chief Executive Officer, its Chief Financial Officer, the members of its Board of Directors and the underwriters that participated in the Company’s IPO are named as defendants in two putative class actions, captioned Douvia v. ON24, Inc., et al., 3:21-cv-08578 (filed November 3, 2021) and Goemer v. ON24, Inc., et al., 3:21-cv-08744 (filed November 10, 2021), that are currently pending in the United States District Court for the Northern District of California. The complaints purport to assert claims on behalf of all persons and entities that purchased, or otherwise acquired, the Company’s common stock issued in connection with the Company’s IPO. The complaints allege that the Company’s registration statement and prospectus contained untrue statements of material fact and/or omitted material facts about ON24’s growth and customer base. Plaintiffs seek, among other things, an award of damages and attorneys’ fees and costs. ON24 believes that the allegations in the lawsuits are without merit. The Company is unable to reasonably estimate a possible loss or range of possible loss, if any, arising from this matter at this early stage. Accordingly, no accrued litigation expense has been recorded in the accompanying condensed consolidated financial statements. In the ordinary course of business, the Company may be subject from time to time to various proceedings, lawsuits, disputes or claims. Although the Company cannot predict with assurance the outcome of any litigation, the Company does not believe there are currently any actions, other than those described in the prior paragraph, that if resolved unfavorably, would have a material impact on its financial condition, results of operations or cash flows.

Convertible Preferred Stock, St

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan	Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan Preferred Stock In connection with the IPO, the Company’s amended and restated certificate of incorporation became effective, which authorized the issuance of 10,000,000 shares of undesignated preferred stock with a par value of $0.0001 per share. The Company’s board of directors is authorized to designate the rights, preferences, privileges and restrictions of the preferred stock from time to time. Convertible Preferred Stock Upon the closing of the IPO in February 2021, all 21,683,548 shares of the Company's outstanding Class A-1 and Class A-2 convertible preferred stock and 5,543,918 shares of Class B and Class B-1 redeemable convertible preferred stock were automatically converted into an aggregate of 27,227,466 shares of common stock on a one-for-one basis. Common Stock The Company’s amended and restated certificate of incorporation authorized the issuance of 500,000,000 shares of common stock, $0.0001 par value per share. Holders of common stock are entitled to one vote per share. Equity Incentive Plan In February 2021 in connection with the IPO, the Company adopted the 2021 Equity Incentive Plan (2021 Plan), which serves as a successor to and continuation of the 2014 Plan and 2000 Plan, collectively the “Predecessor Plans.” All shares that remained available for issuance under the Predecessor Plans as of the closing of the IPO, or that may expire or be canceled or forfeited following the closing of the IPO, become available for future issuance under the 2021 Plan. Under the 2021 Plan, the Company may grant up to 8,282,313 shares of common stock which includes 6,400,000 shares of common stock reserved for issuance under the 2021 Plan, plus an additional 1,882,313 shares reserved for issuance under the 2014 Plan that the Company expects to become available for future issuance under the 2021 Plan . In addition, the number of shares reserved for issuance under the 2021 Plan cumulatively increases on January 1, 2022 and on each subsequent January 1 through and including January 1, 2031, by the lesser of (a) 5% of the number of shares of stock issued and outstanding on the immediately preceding December 31, or (b) an amount determined by the Company’s board of directors. The 2021 Plan provides for the grant of stock o ptions, stock appreciation rights, restricted stock awards, restricted stock units, performance shares, performance units, cash-based awards and other stock-based awards. The plan administrator determines the term of stock options granted under the 2021 Plan, up to a maximum of 10 years. Grant Activities Stock Options A summary of stock option activity under the Company’s equity incentive plans and related information is as follows : Options Outstanding Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (in years) Aggregate Intrinsic Value (in thousands) Balance as of December 31, 2020 11,947,731 $ 4.85 Granted 481,403 50.12 Exercised (1,728,321) 2.48 57,965 Cancelled and forfeited (431,717) 16.25 Balance as of September 30, 2021 10,269,096 $ 6.89 6.8 $ 145,883 Vested and exercisable 5,774,295 $ 2.89 5.3 $ 98,890 Restricted Stock Units (RSUs) A summary of RSU activity under the Company’s equity incentive plans and related information is as follows: RSUs Outstanding Number of Shares Weighted-Average Grant Date Fair Value Unvested balance as of December 31, 2020 — $ — Granted 1,722,750 25.82 Vested (19,039) 31.39 Cancelled and forfeited (48,200) 53.92 Unvested balance as of September 30, 2021 1,655,511 $ 24.94 Restricted Stock Unit with Performance Conditions In June 2014, the Company’s board of directors approved the issuance of 187,500 restricted stock units to an executive officer with a grant date fair value of $0.5 million. No monetary payment was required as a condition to receiving the shares of stock. The award provided that the restricted stock units would vest upon the satisfaction of the following two conditions occurring before June 17, 2021: (i) satisfaction of a service condition of one year and (ii) the occurrence of a liquidity event defined as a change of control or an IPO. The grant date fair value of the awards was not recognized as compensation expense until the performance criteria was probable. Upon the consummation of the Company’s IPO in February 2021, these restricted stock units fully vested and the related stock-based compensation expense of $0.5 million was fully recognized. In accordance with the terms of the grant agreement, these restricted stock units will be settled after the expiration of the lock-up period in the fourth quarter of 2021. Employee Stock Purchase Plan In January 2021, the Company’s board of directors adopted the 2021 Employee Stock Purchase Plan (ESPP), which became effective in connection with the Company’s IPO. A total of 1,300,000 shares of common stock were initially reserved for issuance under the ESPP. The number of shares reserved for issuance cumulatively increases automatically on January 1, 2022 and on each subsequent January 1, through and including January 1, 2031, by the lesser of (a) 1% of the number of shares of stock issued and outstanding on the immediately preceding December 31, (b) 1,300,000 shares, or (c) an amount determined by the Company’s board of directors. All eligible employees may participate in the ESPP and may contribute up to 20% of their earnings (as defined in the ESPP) for the purchase of the Company’s common stock under the ESPP. Unless otherwise determined by the Company’s board of directors, common stock will be purchased for the accounts of employees participating in the ESPP at a price per share equal to the lesser of (1) 85% of the fair market value of a share of the Company’s common stock on the first date of an offering or (2) 85% of the fair market value of a share of the Company’s common stock on the date of purchase. Offering periods generally start on the first trading day on or after May 16 and November 16 of each year, except for the first offering period, which commenced on the effective date of the Company’s IPO and will end on November 15, 2021. As of September 30, 2021, no shares of common stock have been purchased under the ESPP. Fair Value Determination The Black-Scholes assumptions used to value the employee options and the ESPP purchase right at the grant dates are as follows: Employee Stock Options Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Expected term — 6.25 years 5.92 years - 6.07 years 6.25 years Expected volatility — 58.60% 53.82 % - 54.98% 41.60 % - 58.60% Risk-free interest rate — 0.42% 0.62 % - 0.96% 0.42 % - 1.70% Dividend yield —% —% —% —% ESPP Three Months Ended Nine Months Ended Expected term 0.13 years 0.13 years - 0.63 years Expected volatility 34.08 % 34.08 % - 61.00% Risk-free interest rate 0.06 % 0.06% Dividend yield — % —% These assumptions and estimates were determined as follows: • Fair Value of Common Stock. Prior to the Company’s IPO, the fair value was determined by the Company’s board of directors, with input from management and valuation reports prepared by third-party valuation specialists. Stock-based compensation for financial reporting purposes is measured based on updated estimates of fair value when appropriate, such as when additional relevant information related to the estimate becomes available in a valuation report issued as of a subsequent date. For valuations after the consummation of the Company’s IPO, the fair value of each share of underlying common stock is based on the closing price of the Company’s common stock as reported on the date of the grant on the New York Stock Exchange. • Risk-Free Interest Rate . The risk-free interest rate for the expected term of the options is based on the U.S. Treasury yield curve in effect at the time of the grant. • Expected Term . The expected term of options represents the period of time that options are expected to be outstanding. The Company’s historical stock option exercise experience does not provide a reasonable basis upon which to estimate an expected term due to a lack of sufficient data. For stock options granted to employees, the Company estimates the expected term by using the simplified method. The simplified method calculates the expected term as the average of the time-to-vesting and the contractual life of the options. For stock options granted to non-employees, the expected term equals the contractual term of the option. With respect to the ESPP, the expected term is the length of purchase period. • Expected Volatility. As the Company has a short trading history for its common stock, the expected volatility is estimated by taking the average historic price volatility for industry peers, consisting of several public companies in its industry that are similar in size, stage of life cycle, or financial leverage, over a period equivalent to the expected term of the award s. • Expected Dividend Yield. The Company has not declared or paid any cash dividends and does not presently plan to pay cash dividends in the foreseeable future. As a result, an expected dividend yield of zero percent was used. Stock-Based Compensation Effective January 1, 2021, the Company elected to account for forfeited awards as they occur. The stock-based compensation expense by line item in the accompanying condensed consolidated statements of operations is summarized as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Cost of revenue Subscription and other platform $ 607 $ 31 $ 1,190 $ 78 Professional services 109 7 248 16 Total cost of revenue 716 38 1,438 94 Sales and marketing 2,364 162 5,627 450 Research and development 1,235 70 2,879 189 General and administrative 3,516 350 7,851 720 Total stock-based compensation expense $ 7,831 $ 620 $ 17,795 $ 1,453 As of September 30, 2021, unrecognized stock-based compensation expense by award type and their weighted-average recognition periods are as follows (in thousands, except years): Stock Option RSU ESPP Unrecognized stock-based compensation expense $ 51,527 $ 39,293 $ 123 Weighted-average amortization period 3.11 years 3.46 years 0.13 years

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company’s income tax expense (benefit) was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Provision for (benefit from) income taxes $ (32) $ 31 $ (65) $ 123 The Company’s provision for (benefit from) income taxes for interim periods is determined using an estimate of its annual effective tax rate, adjust ed for discrete items, if any. The Company updates its estimate of the annual effective tax rate and makes a year-to-date adjustment to the provision quarterly. Benefit from income taxes for the three and nine months ended September 30, 2021 increased by $0.1 million and $0.2 million, respectively, compared to the three and nine months ended September 30, 2021. The change in benefit from income taxes for each respective period was primarily driven by the tax benefits associated with the exercise of stock options and settlement of restricted stock units in a foreign jurisdiction. The Company regularly performs an assessment on the likelihood of realizing benefits of its deferred tax assets. As of September 30, 2021 , the Company recorded a valuation allowance against its U.S. deferred tax assets based on available evidence. However, if there are favorable changes to actual operating results or to projections of future income, the Company may determine that it is more likely than not that such deferred tax assets may be realizable. Utilization of net operating loss carryforwards, tax credits and other attributes may be subject to future annual limitations due to the ownership change limitations provided by Section 382 of the Internal Revenue Code and similar state provisions.

Net Income (Loss) Per Share Att

Net Income (Loss) Per Share Attributable to Common Stockholders	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Net Income (Loss) Per Share Attributable to Common Stockholders	Net Income (Loss) Per Share Attributable to Common Stockholders The following tables sets forth the computation of basic and diluted net income (loss) per share attributable to common stockholders for the periods presented (in thousands, except share and per share data): Three Months Ended September 30, Nine Months Ended September 30, Basic net income (loss) per share 2021 2020 2021 2020 Net income (loss) $ (9,400) $ 6,605 $ (14,747) $ 11,248 Cumulative preferred dividends allocated to preferred stockholders — (1,467) (558) (4,219) Net income (loss) attributable to common stockholders (9,400) 5,138 (15,305) 7,029 Income available to participating securities — (3,716) — (5,175) Net income (loss) available to common stockholders $ (9,400) $ 1,422 $ (15,305) $ 1,854 Net income (loss) per share of common stock, basic $ (0.20) $ 0.14 $ (0.36) $ 0.19 Weighted-average common stock outstanding, basic 47,101,200 10,420,584 42,149,108 9,755,373 Three Months Ended September 30, Nine Months Ended September 30, Diluted net income (loss) per share 2021 2020 2021 2020 Net income (loss) $ (9,400) $ 6,605 $ (14,747) $ 11,248 Cumulative preferred dividends allocated to preferred stockholders — (1,467) (558) (4,219) Net income (loss) attributable to common stockholders (9,400) 5,138 (15,305) 7,029 Reallocation of earnings to participating securities considering potentially dilutive securities — (3,158) — (4,709) Net income (loss) available to common stockholders $ (9,400) $ 1,980 $ (15,305) $ 2,320 Net income (loss) per share of common stock, diluted $ (0.20) $ 0.12 $ (0.36) $ 0.17 Weighted average common stock outstanding, basic 47,101,200 10,420,584 42,149,108 9,755,373 Weighted average dilutive effect of stock options and restricted stock — 6,647,513 — 3,662,032 Weighted-average common stock outstanding, diluted 47,101,200 17,068,097 42,149,108 13,417,405 The following table sets forth the potential shares of common stock that were excluded from the computation of diluted net income (loss) per share attributable to common stockholders for the periods presented because including them would have been antidilutive: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Convertible preferred stock (on an if-converted basis) — 5,543,918 — 5,543,918 Outstanding stock options 10,269,096 168,922 10,269,096 63,498 Restricted stock units 1,655,511 — 1,655,511 — ESPP purchase rights 96,628 — 96,628 — Total antidilutive securities 12,021,235 5,712,840 12,021,235 5,607,416

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Related Party Transactions	Related Party TransactionsDuring the three and nine months ended September 30, 2021 and 2020, the Company incurred engineering and quality assurance costs from a third-party vendor. The chief executive officer of the third-party vendor is considered an immediate family member of the Company’s chief technology officer. The Company recorded $0.7 million and $1.8 million in the three and nine months ended September 30, 2021, respectively, and $0.4 million and $1.2 million in the three and nine months ended September 30, 2020, respectively, in research and development expense relating to this third party vendor on the condensed consolidated statements of operations. As of September 30, 2021 and December 31, 2020, the Company recorded $0.2 million in accrued liability and $0.2 million in accounts payable and accrued liability, respectively, on the condensed consolidated balance sheets for the amount owed to this third party vendor.

Description of Business and S_2

Description of Business and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Significant Accounting Policies	Basis of Presentation The accompanying condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (U.S. GAAP) and applicable rules and regulations of the Securities and Exchange Commission (SEC) for interim financial reporting. Certain information and note disclosures included in the Company’s annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. Therefore, these condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes included in the Company’s annual report on Form 10-K for the year ended December 31, 2020. In the opinion of management, the condensed consolidated financial statements reflect all adjustments that are normal and recurring in nature and necessary for fair financial statement presentation. All intercompany transactions and balances have been eliminated in consolidation.
Prior Period Reclassification Adjustment	Certain prior period amounts have been reclassified on the condensed consolidated statements of cash flows to conform to the current year's presentation.
Use of Estimates	Use of EstimatesThe preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Significant items subject to such estimates and assumptions include, but are not limited to, the estimated expected benefit period for deferred contract acquisition costs, the determination of standalone selling price for the Company’s performance obligations, the allowance for doubtful accounts and billing reserve, the useful lives of long-lived assets, the estimated value of common stock prior to the IPO and other assumptions used to measure stock-based compensation, the valuation of deferred income tax assets and uncertain tax positions. Actual results could differ from those estimates.
Deferred Offering Costs	Deferred Offering CostsDeferred offering costs consist primarily of accounting, legal and other fees incremental and directly related to the Company’s IPO.
Stock-Based Compensation	Stock-Based Compensation Stock-based compensation expense related to stock awards is recognized based on the fair value of the awards granted. The fair value of each option award is estimated on the grant date using the Black-Scholes option pricing model. The Black-Scholes option pricing model requires the input of highly subjective assumptions, including the fair value of the underlying common stock, the risk-free interest rates, the expected term of the option, the expected volatility of the price of the Company’s common stock and the expected dividend yield of the Company’s common stock. The assumptions used to determine the fair value of the option awards represent management’s best estimates. These estimates involve inherent uncertainties and application of management’s judgement. The related stock-based compensation expense is recognized on a straight-line basis over the requisite service period for each separately vesting portion of the award, which is generally four years. Effective January 1, 2021, the Company elected to account for forfeited awards as they occur. Prior to 2021, the Company estimated the number of awards expected to be forfeited at the time of grant and revised its estimates in subsequent periods if the actual forfeitures differed from the estimates. This change in accounting policy did not have a material impact on the Company’s condensed consolidated financial statements.
Recently Adopted Accounting Standards	Recently Adopted Accounting Standards In December 2019, the FASB issued ASU No. 2019-12, Income Taxes Topic 740: Simplifying the Accounting for Income Taxes , which removes a variety of exceptions within the framework of ASC 740. These include the exception to the incremental approach for intraperiod tax allocation in the event of a loss from continuing operations and income or a gain from other items (such as other comprehensive income), and the exception to using general methodology for the interim period tax accounting for year-to-date losses that exceed anticipated losses. For public business entities, ASU No. 2019-12 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2020. For all other entities, ASU No. 2019-12 is effective for fiscal years beginning after December 15, 2021, and interim periods within fiscal years beginning after December 15, 2022. Early adoption of the amendments is permitted, including adoption in any interim period for (1) public business entities for periods for which financial statements have not yet been issued and (2) all other entities for periods for which financial statements have not yet been made available for issuance. The adoption of this standard did not have a material impact on its condensed consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles-Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract . This new standard requires an entity (customer) in a hosting arrangement that is a service contract to follow the guidance in Subtopic 350-40 to determine which implementation costs to capitalize as an asset related to the service contract and which costs to expense. Costs for implementation activities in the application development stage can be capitalized depending on the nature of the costs, while costs incurred during the preliminary project and post-implementation stages are expensed as the activities are performed. The costs capitalized are expensed over the term of the hosting arrangement. The amendments in ASU No. 2018-15 also require the entity to present the expense related to the capitalized implementation costs in the same line item in the statement of income as the fees associated with the hosting element (service) of the arrangement and classify payments for capitalized implementation costs in the statement of cash flows in the same manner as payments made for fees associated with the hosting element. ASU No. 2018-15 is effective for public business entities for fiscal years beginning after December 15, 2019, and interim periods within those fiscal years. For all other entities, ASU No. 2018-15 is effective for annual reporting periods beginning after December 15, 2020, and interim periods within annual periods beginning after December 15, 2021. ASU No. 2018-15 should be applied either retrospectively or prospectively to all implementation costs incurred after the date of adoption. The Company adopted ASU No. 2018-15 effective January 1, 2021 using a prospective approach. The adoption of this standard did not have a material impact on its condensed consolidated financial statements.

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2021
Disaggregation Of Revenue [Line Items]
Schedule of Disaggregation of Revenue by Geographic Region	The following table depicts the disaggregation of revenue by geographic region based on the shipping address of customers (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 United States $ 36,922 $ 32,510 $ 112,212 $ 80,015 EMEA 8,524 6,981 27,382 16,807 Other 3,916 3,098 11,985 6,833 Total revenue $ 49,362 $ 42,589 $ 151,579 $ 103,655
Summary of Revenue by Digital Experience Platform and Legacy Offering	The following table summarizes revenue by digital experience platform and Legacy offering (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Digital experience platform - subscription and other platform $ 43,564 $ 34,297 $ 130,789 $ 80,010 Digital experience platform - professional services 5,761 8,183 20,666 21,705 Legacy - subscription and other platform 37 59 99 1,369 Legacy - professional services — 50 25 571 Total revenue $ 49,362 $ 42,589 $ 151,579 $ 103,655
Geographic Concentration Risk | Revenue
Disaggregation Of Revenue [Line Items]
Schedule of Foreign Countries Which Contributed 10% or More of Total Revenue	The following table summarizes the foreign countries which contributed 10% or more of the total revenue (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 United Kingdom * * 11 % * * Represent less than 10% of total revenue

Marketable Securities (Tables)

Marketable Securities (Tables)	9 Months Ended
	Sep. 30, 2021
Marketable Securities [Abstract]
Summary of Marketable Securities	Marketable securities consisted of the following as of the periods presented (in thousands): September 30, 2021 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Marketable Securities U.S. Treasury securities $ 136,386 $ 4 $ (25) $ 136,365 Certificates of deposit 6,495 — — 6,495 Corporate debt securities 39,836 4 (15) 39,825 Commercial papers 8,236 2 — 8,238 Asset-backed securities 10,976 1 (4) 10,973 Total marketable securities $ 201,929 $ 11 $ (44) $ 201,896 December 31, 2020 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Value Marketable Securities Certificates of deposit $ 3,000 $ — $ — $ 3,000 Total marketable securities $ 3,000 $ — $ — $ 3,000
Summary of Remaining Contractual Maturities of Marketable Securities	The following summarizes the remaining contractual maturities of the Company’s marketable securities as of September 30, 2021 : Fair Value One year or less $ 46,601 Over one year through five years 155,295 Total marketable securities $ 201,896

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Summary of Financial Instruments Recorded at Fair Value on Recurring Basis	The following tables summarizes our financial instruments recorded at fair value on a recurring basis by level within the fair value hierarchy as of the periods presented September 30, 2021 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 170,768 $ — $ — $ 170,768 Marketable Securities U.S. Treasury securities — 136,365 — 136,365 Certificates of deposit — 6,495 — 6,495 Corporate debt securities — 39,825 — 39,825 Commercial papers — 8,238 — 8,238 Asset-backed securities — 10,973 — 10,973 Total cash equivalents and marketable securities $ 170,768 $ 201,896 $ — $ 372,664 December 31, 2020 Level 1 Level 2 Level 3 Total Cash equivalents Money market funds $ 2,027 $ — $ — $ 2,027 Marketable Securities — Certificates of deposit 3,000 — — 3,000 Total cash equivalents and marketable securities $ 5,027 $ — $ — $ 5,027

Balance Sheets Components (Tabl

Balance Sheets Components (Tables)	9 Months Ended
	Sep. 30, 2021
Balance Sheet Related Disclosures [Abstract]
Summary of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following as of the periods presented (in thousands): September 30, 2021 December 31, 2020 Deferred offering costs $ — $ 3,220 Prepaid expenses 6,611 2,848 Other receivables 2,460 873 Other 590 138 Prepaid expenses and other current assets $ 9,661 $ 7,079
Summary of Property and Equipment, Net	Property and equipment, net consisted of the following as of the periods presented (in thousands): September 30, 2021 December 31, 2020 Computer, equipment and software (1) $ 27,315 $ 24,175 Furniture and fixtures 1,116 1,108 Leasehold improvements 3,708 3,708 Property and equipment, gross 32,139 28,991 Less: Accumulated depreciation and amortization (2) (23,290) (19,940) Property and equipment, net $ 8,849 $ 9,051 (1) Includes assets recorded under capital leases of $6.1 million and $6.9 million as of September 30, 2021 and December 31, 2020, respectively. (2) Includes amount for assets recorded under capital leases of $2.4 million and $2.2 million as of September 30, 2021 and December 31, 2020, respectively.
Schedule of Property and Equipment, Net of Depreciation and Amortization, by Geographic Region	The following table presents the property and equipment, net of depreciation and amortization, by geographic region (in thousands): September 30, 2021 December 31, 2020 United States $ 8,556 $ 8,698 EMEA 240 308 Other 53 45 Total property and equipment, net $ 8,849 $ 9,051
Summary of Accrued Liabilities	Accrued liabilities consisted of the following as of the periods presented (in thousands): September 30, 2021 December 31, 2020 Accrued bonus $ 3,063 $ 2,785 Accrued vacation 3,444 2,724 Accrued commissions 2,022 3,149 Accrued ESPP 2,495 — Sales and other tax liabilities 477 1,086 Accrued liability for unsettled investment trades 3,482 — Other 8,006 7,695 Accrued liabilities $ 22,989 $ 17,439
Summary of Other Long-Term Liabilities	Other long-term liabilities consisted of the following as of the periods presented (in thousands): September 30, 2021 December 31, 2020 Deferred rent liabilities $ 2,118 $ 2,543 Deferred revenue 896 1,152 Other 360 327 Other long-term liabilities $ 3,374 $ 4,022

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Summary of Debt	Debt consisted of the following as of the periods presented (in thousands): September 30, 2021 December 31, 2020 Revolving line of credit $ — $ 22,350 Equipment loan agreements 643 438 Capital leases 4,028 5,298 Total debt 4,671 28,086 Less: Current portion (2,128) (2,359) Total long-term debt $ 2,543 $ 25,727
Schedule of Future Payments Under Equipment Loan Agreements and Capital Lease Obligations	As of September 30, 2021, future payments under the equipment loan agreements and capital lease obligations, are as follows (in thousands): Equipment Loans Capital Leases Total Remainder of 2021 $ 65 $ 432 $ 497 2022 271 2,074 2,345 2023 236 1,671 1,907 2024 71 71 142 Total payments 643 4,248 4,891 Less: Amount representing interest — 220 220 Total payments, net of interest $ 643 $ 4,028 $ 4,671

Convertible Preferred Stock, _2

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - (Tables)	9 Months Ended
	Sep. 30, 2021
Equity [Abstract]
Summary of Stock Options	A summary of stock option activity under the Company’s equity incentive plans and related information is as follows : Options Outstanding Number of Shares Weighted- Average Exercise Price Weighted- Average Remaining Contractual Life (in years) Aggregate Intrinsic Value (in thousands) Balance as of December 31, 2020 11,947,731 $ 4.85 Granted 481,403 50.12 Exercised (1,728,321) 2.48 57,965 Cancelled and forfeited (431,717) 16.25 Balance as of September 30, 2021 10,269,096 $ 6.89 6.8 $ 145,883 Vested and exercisable 5,774,295 $ 2.89 5.3 $ 98,890
Summary of RSU Activity Under Equity Incentive Plans and Related Information	A summary of RSU activity under the Company’s equity incentive plans and related information is as follows: RSUs Outstanding Number of Shares Weighted-Average Grant Date Fair Value Unvested balance as of December 31, 2020 — $ — Granted 1,722,750 25.82 Vested (19,039) 31.39 Cancelled and forfeited (48,200) 53.92 Unvested balance as of September 30, 2021 1,655,511 $ 24.94
Schedule of Black-Scholes Assumptions Used to Value the Employee Stock Options	Employee Stock Options Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Expected term — 6.25 years 5.92 years - 6.07 years 6.25 years Expected volatility — 58.60% 53.82 % - 54.98% 41.60 % - 58.60% Risk-free interest rate — 0.42% 0.62 % - 0.96% 0.42 % - 1.70% Dividend yield —% —% —% —%
Schedule of Black-Scholes Assumptions Used to Value the ESPP	ESPP Three Months Ended Nine Months Ended Expected term 0.13 years 0.13 years - 0.63 years Expected volatility 34.08 % 34.08 % - 61.00% Risk-free interest rate 0.06 % 0.06% Dividend yield — % —%
Summary of Share-based Compensation Expense by line item in the Condensed Consolidated Statements of Operations	The stock-based compensation expense by line item in the accompanying condensed consolidated statements of operations is summarized as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Cost of revenue Subscription and other platform $ 607 $ 31 $ 1,190 $ 78 Professional services 109 7 248 16 Total cost of revenue 716 38 1,438 94 Sales and marketing 2,364 162 5,627 450 Research and development 1,235 70 2,879 189 General and administrative 3,516 350 7,851 720 Total stock-based compensation expense $ 7,831 $ 620 $ 17,795 $ 1,453
Summary of Unrecognized Stock-Based Compensation Expenses	As of September 30, 2021, unrecognized stock-based compensation expense by award type and their weighted-average recognition periods are as follows (in thousands, except years): Stock Option RSU ESPP Unrecognized stock-based compensation expense $ 51,527 $ 39,293 $ 123 Weighted-average amortization period 3.11 years 3.46 years 0.13 years

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Schedule of Income Tax Expense (Benefit)	The Company’s income tax expense (benefit) was as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Provision for (benefit from) income taxes $ (32) $ 31 $ (65) $ 123

Net Income (Loss) Per Share A_2

Net Income (Loss) Per Share Attributable to Common Stockholders (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of Computation of Basic and Diluted Net Loss Per Share	The following tables sets forth the computation of basic and diluted net income (loss) per share attributable to common stockholders for the periods presented (in thousands, except share and per share data): Three Months Ended September 30, Nine Months Ended September 30, Basic net income (loss) per share 2021 2020 2021 2020 Net income (loss) $ (9,400) $ 6,605 $ (14,747) $ 11,248 Cumulative preferred dividends allocated to preferred stockholders — (1,467) (558) (4,219) Net income (loss) attributable to common stockholders (9,400) 5,138 (15,305) 7,029 Income available to participating securities — (3,716) — (5,175) Net income (loss) available to common stockholders $ (9,400) $ 1,422 $ (15,305) $ 1,854 Net income (loss) per share of common stock, basic $ (0.20) $ 0.14 $ (0.36) $ 0.19 Weighted-average common stock outstanding, basic 47,101,200 10,420,584 42,149,108 9,755,373 Three Months Ended September 30, Nine Months Ended September 30, Diluted net income (loss) per share 2021 2020 2021 2020 Net income (loss) $ (9,400) $ 6,605 $ (14,747) $ 11,248 Cumulative preferred dividends allocated to preferred stockholders — (1,467) (558) (4,219) Net income (loss) attributable to common stockholders (9,400) 5,138 (15,305) 7,029 Reallocation of earnings to participating securities considering potentially dilutive securities — (3,158) — (4,709) Net income (loss) available to common stockholders $ (9,400) $ 1,980 $ (15,305) $ 2,320 Net income (loss) per share of common stock, diluted $ (0.20) $ 0.12 $ (0.36) $ 0.17 Weighted average common stock outstanding, basic 47,101,200 10,420,584 42,149,108 9,755,373 Weighted average dilutive effect of stock options and restricted stock — 6,647,513 — 3,662,032 Weighted-average common stock outstanding, diluted 47,101,200 17,068,097 42,149,108 13,417,405
Schedule of Potential Shares of Common Stock Excluded from Computation of Diluted Net Loss Per Share	The following table sets forth the potential shares of common stock that were excluded from the computation of diluted net income (loss) per share attributable to common stockholders for the periods presented because including them would have been antidilutive: Three Months Ended September 30, Nine Months Ended September 30, 2021 2020 2021 2020 Convertible preferred stock (on an if-converted basis) — 5,543,918 — 5,543,918 Outstanding stock options 10,269,096 168,922 10,269,096 63,498 Restricted stock units 1,655,511 — 1,655,511 — ESPP purchase rights 96,628 — 96,628 — Total antidilutive securities 12,021,235 5,712,840 12,021,235 5,607,416

Description of Business and S_3

Description of Business and Significant Accounting Policies - Additional Information (Details) $ / shares in Units, $ in Thousands	Feb. 05, 2021USD ($)$ / sharesshares	Sep. 30, 2021USD ($)shares	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Description of Business and Significant Accounting Policies [Line Items]
Proceeds from initial public offering, net of underwriting discounts		$ 353,397	$ 0
Payments of offering costs		3,481	$ 0
Deferred offering costs within prepaid expenses and other current asset/ reclassified into stockholders' equity (deficit)		$ 0		$ 3,220
Requisite service period		4 years
Prepaid Expenses and Other Current Assets
Description of Business and Significant Accounting Policies [Line Items]
Deferred offering costs within prepaid expenses and other current asset/ reclassified into stockholders' equity (deficit)				$ 3,200
IPO
Description of Business and Significant Accounting Policies [Line Items]
Convertible preferred stock converted into shares of common stock (in shares) | shares	27,227,466
Common Stock
Description of Business and Significant Accounting Policies [Line Items]
Issuance of common stock upon initial public offering, net of underwriting discounts and other offering costs (in shares) | shares		7,599,928
Convertible preferred stock converted into shares of common stock (in shares) | shares		27,227,466
Common Stock | IPO
Description of Business and Significant Accounting Policies [Line Items]
Issuance of common stock upon initial public offering, net of underwriting discounts and other offering costs (in shares) | shares	7,599,928
Offering price (in dollars per share) | $ / shares	$ 50
Proceeds from initial public offering, net of underwriting discounts	$ 348,000
Payments of offering costs	26,600
Other offering costs	$ 5,400
Convertible preferred stock converted into shares of common stock (in shares) | shares	27,227,466
Conversion of convertible preferred stock to common stock, ratio	1
Additional Paid-in Capital
Description of Business and Significant Accounting Policies [Line Items]
Deferred offering costs within prepaid expenses and other current asset/ reclassified into stockholders' equity (deficit)	$ 5,400

Revenue - Schedule of Disaggreg

Revenue - Schedule of Disaggregation of Revenue by Geographic Region (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Total revenue	$ 49,362	$ 42,589	$ 151,579	$ 103,655
United States
Disaggregation Of Revenue [Line Items]
Total revenue	36,922	32,510	112,212	80,015
EMEA
Disaggregation Of Revenue [Line Items]
Total revenue	8,524	6,981	27,382	16,807
Other
Disaggregation Of Revenue [Line Items]
Total revenue	$ 3,916	$ 3,098	$ 11,985	$ 6,833

Revenue - Foreign Countries Whi

Revenue - Foreign Countries Which Contributed 10% or more of Total Revenue (Detail)	9 Months Ended
	Sep. 30, 2021
Geographic Concentration Risk | Revenue | United Kingdom
Disaggregation Of Revenue [Line Items]
Percentage of concentration risk	11.00%

Revenue - Summary of Revenue by

Revenue - Summary of Revenue by Digital Experience Platform and Legacy Offering (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Total revenue	$ 49,362	$ 42,589	$ 151,579	$ 103,655
Digital experience platform - subscription and other platform
Disaggregation Of Revenue [Line Items]
Total revenue	43,564	34,297	130,789	80,010
Digital experience platform - professional services
Disaggregation Of Revenue [Line Items]
Total revenue	5,761	8,183	20,666	21,705
Legacy - subscription and other platform
Disaggregation Of Revenue [Line Items]
Total revenue	37	59	99	1,369
Legacy - professional services
Disaggregation Of Revenue [Line Items]
Total revenue	$ 0	$ 50	$ 25	$ 571

Revenue - Contract Balances and

Revenue - Contract Balances and Costs To Obtain A Contract (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation Of Revenue [Line Items]
Revenue recognized related to deferred revenue	$ 14,800,000		$ 80,200,000
Capitalized contract cost, amortization period	5 years		5 years
Amortization of deferred contract acquisition cost			$ 11,305,000	$ 7,460,000
Impairment losses of deferred contract acquisition costs	$ 0	$ 0	0	0
Sales and Marketing Expense
Disaggregation Of Revenue [Line Items]
Amortization of deferred contract acquisition cost	$ 3,800,000	$ 3,200,000	$ 11,300,000	$ 7,500,000

Revenue - Remaining Performance

Revenue - Remaining Performance Obligations (Details) $ in Millions	Sep. 30, 2021USD ($)
Disaggregation Of Revenue [Line Items]
Remaining performance obligation	$ 143.8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2021-10-01
Disaggregation Of Revenue [Line Items]
Remaining performance obligation percentage	81.00%
Revenue remaining performance obligation, expected timing of satisfaction period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2022-10-01
Disaggregation Of Revenue [Line Items]
Revenue remaining performance obligation, expected timing of satisfaction period
Billed Consideration
Disaggregation Of Revenue [Line Items]
Remaining performance obligation	$ 92
Unbilled Consideration
Disaggregation Of Revenue [Line Items]
Remaining performance obligation	$ 51.8

Marketable Securities - Summary

Marketable Securities - Summary of Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Marketable Securities [Line Items]
Total marketable securities, Amortized Cost	$ 201,929	$ 3,000
Total marketable securities, Gross Unrealized Gains	11	0
Total marketable securities, Gross Unrealized Losses	(44)	0
Total marketable securities, fair value	201,896	3,000
U.S. Treasury securities
Marketable Securities [Line Items]
Total marketable securities, Amortized Cost	136,386
Total marketable securities, Gross Unrealized Gains	4
Total marketable securities, Gross Unrealized Losses	(25)
Total marketable securities, fair value	136,365
Certificates of deposit
Marketable Securities [Line Items]
Total marketable securities, Amortized Cost	6,495	3,000
Total marketable securities, Gross Unrealized Gains	0	0
Total marketable securities, Gross Unrealized Losses	0	0
Total marketable securities, fair value	6,495	$ 3,000
Corporate debt securities
Marketable Securities [Line Items]
Total marketable securities, Amortized Cost	39,836
Total marketable securities, Gross Unrealized Gains	4
Total marketable securities, Gross Unrealized Losses	(15)
Total marketable securities, fair value	39,825
Commercial papers
Marketable Securities [Line Items]
Total marketable securities, Amortized Cost	8,236
Total marketable securities, Gross Unrealized Gains	2
Total marketable securities, Gross Unrealized Losses	0
Total marketable securities, fair value	8,238
Asset-backed securities
Marketable Securities [Line Items]
Total marketable securities, Amortized Cost	10,976
Total marketable securities, Gross Unrealized Gains	1
Total marketable securities, Gross Unrealized Losses	(4)
Total marketable securities, fair value	$ 10,973

Marketable Securities - Additio

Marketable Securities - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Marketable Securities (Available For Sale) [Line Items]
Marketable securities in a continuous loss position for 12 months or more	$ 0		$ 0		$ 0
Decline deemed to be other-than-temporary			0
Reclassification out of Accumulated Other Comprehensive Income (Loss)
Marketable Securities (Available For Sale) [Line Items]
Realized gains (losses) from marketable securities	$ 0	$ 0	$ 0	$ 0

Marketable Securities - Summa_2

Marketable Securities - Summary of Remaining Contractual Maturities of Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Marketable Securities (Available For Sale) Maturities [Abstract]
One year or less	$ 46,601
Over one year through five years	155,295
Total marketable securities	$ 201,896	$ 3,000

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Financial Instruments Recorded at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	$ 201,896	$ 3,000
U.S. Treasury securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	136,365
Certificates of deposit
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	6,495	3,000
Corporate debt securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	39,825
Commercial papers
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	8,238
Asset-backed securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	10,973
Fair Value Measurements Recurring
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total cash equivalents and marketable securities	372,664	5,027
Fair Value Measurements Recurring | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total cash equivalents and marketable securities	170,768	5,027
Fair Value Measurements Recurring | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total cash equivalents and marketable securities	201,896	0
Fair Value Measurements Recurring | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total cash equivalents and marketable securities	0	0
Fair Value Measurements Recurring | Money market funds
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Money market funds, fair value	170,768	2,027
Fair Value Measurements Recurring | Money market funds | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Money market funds, fair value	170,768	2,027
Fair Value Measurements Recurring | Money market funds | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Money market funds, fair value	0	0
Fair Value Measurements Recurring | Money market funds | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Money market funds, fair value	0	0
Fair Value Measurements Recurring | U.S. Treasury securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	136,365
Fair Value Measurements Recurring | U.S. Treasury securities | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0
Fair Value Measurements Recurring | U.S. Treasury securities | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	136,365
Fair Value Measurements Recurring | U.S. Treasury securities | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0
Fair Value Measurements Recurring | Certificates of deposit
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	6,495	3,000
Fair Value Measurements Recurring | Certificates of deposit | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0	3,000
Fair Value Measurements Recurring | Certificates of deposit | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	6,495	0
Fair Value Measurements Recurring | Certificates of deposit | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0	$ 0
Fair Value Measurements Recurring | Corporate debt securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	39,825
Fair Value Measurements Recurring | Corporate debt securities | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0
Fair Value Measurements Recurring | Corporate debt securities | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	39,825
Fair Value Measurements Recurring | Corporate debt securities | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0
Fair Value Measurements Recurring | Commercial papers
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	8,238
Fair Value Measurements Recurring | Commercial papers | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0
Fair Value Measurements Recurring | Commercial papers | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	8,238
Fair Value Measurements Recurring | Commercial papers | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0
Fair Value Measurements Recurring | Asset-backed securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	10,973
Fair Value Measurements Recurring | Asset-backed securities | Level 1
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	0
Fair Value Measurements Recurring | Asset-backed securities | Level 2
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	10,973
Fair Value Measurements Recurring | Asset-backed securities | Level 3
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Total marketable securities, fair value	$ 0

Balance Sheets Components - Sum

Balance Sheets Components - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Deferred offering costs	$ 0	$ 3,220
Prepaid expenses	6,611	2,848
Other receivables	2,460	873
Other	590	138
Prepaid expenses and other current assets	$ 9,661	$ 7,079

Balance Sheets Components - S_2

Balance Sheets Components - Summary of Property and Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 32,139	$ 28,991
Less: Accumulated depreciation and amortization	(23,290)	(19,940)
Property and equipment, net	8,849	9,051
Computer, equipment and software
Property Plant And Equipment [Line Items]
Property and equipment, gross	27,315	24,175
Furniture and fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,116	1,108
Leasehold improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 3,708	$ 3,708

Balance Sheets Components - Add

Balance Sheets Components - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 32,139		$ 32,139		$ 28,991
Accumulated depreciation and amortization	23,290		23,290		19,940
Depreciation and amortization	1,100	$ 700	3,423	$ 1,930
Assets recorded under capital leases
Property Plant And Equipment [Line Items]
Property and equipment, gross	6,100		6,100		6,900
Accumulated depreciation and amortization	$ 2,400		$ 2,400		$ 2,200

Balance Sheets Components - Sch

Balance Sheets Components - Schedule of Property and Equipment, Net of Depreciation and Amortization, by Geographic Region (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property and equipment, net	$ 8,849	$ 9,051
United States
Property Plant And Equipment [Line Items]
Total property and equipment, net	8,556	8,698
EMEA
Property Plant And Equipment [Line Items]
Total property and equipment, net	240	308
Other
Property Plant And Equipment [Line Items]
Total property and equipment, net	$ 53	$ 45

Balance Sheets Components - S_3

Balance Sheets Components - Summary of Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Accrued bonus	$ 3,063	$ 2,785
Accrued vacation	3,444	2,724
Accrued commissions	2,022	3,149
Accrued ESPP	2,495	0
Sales and other tax liabilities	477	1,086
Accrued liability for unsettled investment trades	3,482	0
Other	8,006	7,695
Accrued liabilities	$ 22,989	$ 17,439

Balance Sheets Components - S_4

Balance Sheets Components - Summary of Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Balance Sheet Related Disclosures [Abstract]
Deferred rent liabilities	$ 2,118	$ 2,543
Deferred revenue	896	1,152
Other	360	327
Other long-term liabilities	$ 3,374	$ 4,022

Debt - Summary of Debt (Details

Debt - Summary of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total debt	$ 4,671	$ 28,086
Less: Current portion	(2,128)	(2,359)
Total long-term debt	2,543	25,727
Equipment Loan Agreements
Debt Instrument [Line Items]
Total debt	643	438
Capital Leases
Debt Instrument [Line Items]
Total debt	4,028	5,298
Revolving Line of Credit
Debt Instrument [Line Items]
Total debt	$ 0	$ 22,350

Debt - Revolving Line of Credit

Debt - Revolving Line of Credit (Details) - USD ($)	Jul. 31, 2020	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2021	Sep. 30, 2020
Debt Instrument [Line Items]
Repayments of long-term debt				$ 22,532,000	$ 18,129,000
Revolving Line of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 50,000,000		50,000,000
Cash to be maintained per agreement		$ 100,000,000		$ 100,000,000
Deferred revenue trailing period				5 months
Percentage of unused facility fee to be paid quarterly		0.15%
Current portion of total borrowing amount, subject to maximum debt to EBITDA ratio, financial covenant				$ 5,000,000
Repayments of long-term debt			$ 22,400,000
Revolving Line of Credit | Prime Rate
Debt Instrument [Line Items]
Margin on interest rate	0.75%
Debt instrument, interest rate		3.25%		3.25%	3.25%
Letter of Credit
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 4,000,000		$ 4,000,000
Letter of Credit | Property Lease Guarantee
Debt Instrument [Line Items]
Letters of credit outstanding, amount		1,200,000		1,200,000
Credit Card Sublimit
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 1,000,000		$ 1,000,000

Debt - Equipment Loan Agreement

Debt - Equipment Loan Agreements (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total debt	$ 4,671	$ 28,086
Equipment Loan Agreements
Debt Instrument [Line Items]
Total debt	$ 643	$ 438
Maximum | Equipment Loan Agreements
Debt Instrument [Line Items]
Repayment period	36 months
Debt instrument, interest rate	10.10%
Minimum | Equipment Loan Agreements
Debt Instrument [Line Items]
Debt instrument, interest rate	5.80%

Debt - Future Payments Under Eq

Debt - Future Payments Under Equipment Loan Agreements and Capital Lease Obligations (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Equipment Loans, remainder of 2021	$ 65
Equipment Loans, 2022	271
Equipment Loans, 2023	236
Equipment Loans, 2024	71
Equipment Loans, Total payments	643
Equipment loan, Less: Amount representing interest	0
Equipment Loans, Total payments, net of interest	643
Capital leases, remainder of 2021	432
Capital leases, 2022	2,074
Capital leases, 2023	1,671
Capital leases, 2024	71
Total payments	4,248
Capital leases, Less: Amount representing interest	220
Total payments, net of interest	4,028
Remainder of 2021	497
2022	2,345
2023	1,907
2024	142
Total payments	4,891
Less: Amount representing interest	220
Total debt	$ 4,671	$ 28,086

Commitment and Contingencies -

Commitment and Contingencies - Purchase Obligations (Details) - Software License Fees And Co-Location Facilities And Services $ in Millions	Sep. 30, 2021USD ($)
Loss Contingencies [Line Items]
Non-cancelable purchase commitments	$ 6
Non-cancelable purchase commitments, due remainder of fiscal year	0.7
Non-cancelable purchase commitments, due 2022	3.5
Non-cancelable purchase commitments, due 2023	1.7
Non-cancelable purchase commitments, due 2024	$ 0.1

Commitment and Contingencies _2

Commitment and Contingencies - Contingencies and Legal Proceedings (Details)	Nov. 03, 2021USD ($)putativeClassActions	Sep. 30, 2021USD ($)	Dec. 31, 2020USD ($)
Subsequent Event | Putative Class Actions Douvia v ON24 And Goemer v ON24 | Pending Litigation
Loss Contingencies [Line Items]
Number of pending claims | putativeClassActions	2
Accrued litigation expense	$ 0
Sales and Use Tax Assessments
Loss Contingencies [Line Items]
Loss contingency, range of possible loss, portion not accrued		$ 0	$ 0
Sales and Use Tax Assessments | Minimum
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss		0
Sales and Use Tax Assessments | Maximum
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss		$ 1,800,000

Convertible Preferred Stock, _3

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Preferred Stock (Details) - Undesignated Preferred Stock - IPO	Feb. 05, 2021$ / sharesshares
Class Of Stock [Line Items]
Undesignated preferred stock shares authorized (in shares) | shares	10,000,000
Undesignated referred stock par value (in dollars per share) | $ / shares	$ 0.0001

Convertible Preferred Stock, _4

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Convertible Preferred Stock (Details)	Feb. 05, 2021shares	Sep. 30, 2021shares	Dec. 31, 2020shares
IPO
Class Of Stock [Line Items]
Convertible preferred stock converted into shares of common stock (in shares)	27,227,466
Redeemable preferred stock convertible to common stock conversion ratio	1
Convertible Class A-1 and Class A-2 Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock outstanding (in shares)		0	21,683,548
Convertible Class A-1 and Class A-2 Preferred Stock | IPO
Class Of Stock [Line Items]
Convertible preferred stock outstanding (in shares)	21,683,548
Redeemable Convertible Class B and Class B-1 Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock outstanding (in shares)		0	5,543,918
Redeemable Convertible Class B and Class B-1 Preferred Stock | IPO
Class Of Stock [Line Items]
Convertible preferred stock outstanding (in shares)	5,543,918

Convertible Preferred Stock, _5

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Common Stock (Details)	Feb. 05, 2021Vote$ / sharesshares	Sep. 30, 2021$ / sharesshares	Dec. 31, 2020$ / sharesshares
Class Of Stock [Line Items]
Common stock, authorized (in shares)		500,000,000	50,000,000
Common stock, par value (in dollars per share) | $ / shares	$ 0.0001	$ 0.0001	$ 0.0001
Number of votes per share | Vote	1
Common Stock
Class Of Stock [Line Items]
Common stock, authorized (in shares)	500,000,000

Convertible Preferred Stock, _6

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Equity Incentive Plan (Details)	Feb. 05, 2021shares
2021 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, shares available for grant (in shares)	8,282,313
Number of shares available for future issuance (in shares)	6,400,000
Percent of outstanding stock from Jan 1, 2022 to Jan 1, 2031, maximum	5.00%
2021 Plan | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Term of stock options granted	10 years
2014 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Numbers of additional shares authorized from Jan 1, 2022 to Jan 1, 2031 under the plan	1,882,313

Convertible Preferred Stock, _7

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Summary of Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2021
Number of Shares
Beginning balance (in shares)	11,947,731
Granted (in shares)	481,403
Exercised (in shares)	(1,728,321)
Cancelled and forfeited (in shares)	(431,717)
Ending balance (in shares)	10,269,096
Vested and exercisable (in shares)	5,774,295
Weighted- Average Exercise Price
Beginning balance (in dollars per share)	$ 4.85
Granted (in dollars per share)	50.12
Exercised (in dollars per share)	2.48
Cancelled and forfeited (in dollars per share)	16.25
Ending Balance (in dollars per share)	6.89
Vested and exercisable (in dollars per share)	$ 2.89
Ending balance, Weighted Average Remaining Contractual Life	6 years 9 months 18 days
Vested and exercisable, Weighted Average Remaining Contractual Life	5 years 3 months 18 days
Exercise, aggregate intrinsic value	$ 57,965
Outstanding ending balance, aggregate intrinsic value	145,883
Vested and exercisable, aggregate intrinsic value	$ 98,890

Convertible Preferred Stock, _8

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Summary of RSU Activity Under Equity Incentive Plans and Related Information (Details) - Restricted stock units	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Number of Shares
Unvested beginning balance (in shares) | shares	0
Granted (in shares) | shares	1,722,750
Vested (in shares) | shares	(19,039)
Cancelled and forfeited (in shares) | shares	(48,200)
Unvested ending balance (in shares) | shares	1,655,511
Weighted-Average Grant Date Fair Value
Unvested beginning balance (in dollars per share) | $ / shares	$ 0
Granted (in dollars per share) | $ / shares	25.82
Vested (in dollars per share) | $ / shares	31.39
Cancelled and forfeited (in dollars per share) | $ / shares	53.92
Unvested ending balance (in dollars per share) | $ / shares	$ 24.94

Convertible Preferred Stock, _9

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Restricted Stock Unit with Performance Conditions (Details) - USD ($)	Feb. 02, 2021	Feb. 28, 2021	Jun. 30, 2014	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Requisite service period						4 years
Stock-based compensation expense				$ 7,831,000	$ 620,000	$ 17,795,000	$ 1,453,000
Restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares vested (in shares)						19,039
Granted (in shares)						1,722,750
Executive Officer | Restricted stock units | Share-based Payment Arrangement, Employee
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares vested (in shares)	187,500
Granted (in shares)			187,500
Grant date fair value			$ 500,000
Payment to receive shares of stock			$ 0
Requisite service period			1 year
Stock-based compensation expense		$ 500,000

Convertible Preferred Stock,_10

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Employee Stock Purchase Plan (Details) - Employee Stock - shares	1 Months Ended	9 Months Ended
	Jan. 31, 2021	Sep. 30, 2021
Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of employees earnings contribution for purchase of common stock under ESPP	20.00%
Purchase of common stock under ESPP (in shares)		0
Common Stock | First Date of ESPP Offering
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of purchase price of common stock to fair market value of common stock on offering or purchase date	85.00%
Common Stock | Date of Purchase of ESPP Offering
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of purchase price of common stock to fair market value of common stock on offering or purchase date	85.00%
2021 Employee Stock Purchase Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percent of outstanding stock from Jan 1, 2022 to Jan 1, 2031, maximum	1.00%
Numbers of additional shares authorized from Jan 1, 2022 to Jan 1, 2031 under the plan	1,300,000
2021 Employee Stock Purchase Plan | Common Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for future issuance (in shares)	1,300,000

Convertible Preferred Stock,_11

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Expected Dividend Yield (Details) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Cash dividends payment (in dollars per share)	$ 0	$ 0	$ 0	$ 0
Declared cash dividends (in dollars per share)	$ 0	$ 0	$ 0	$ 0
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Dividend yield	0.00%	0.00%	0.00%	0.00%

Convertible Preferred Stock,_12

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Schedule of Black-Scholes Assumptions Used to Value the Employee Stock Options (Detail) - Employee Stock Option	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term		6 years 3 months		6 years 3 months
Expected volatility, minimum			53.82%	41.60%
Expected volatility, maximum			54.98%	58.60%
Expected volatility		58.60%
Risk-free interest rate, minimum			0.62%	0.42%
Risk-free interest rate, maximum			0.96%	1.70%
Risk-free interest rate		0.42%
Dividend yield	0.00%	0.00%	0.00%	0.00%
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term			5 years 11 months 1 day
Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term			6 years 25 days

Convertible Preferred Stock,_13

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Schedule of Black-Scholes Assumptions Used to Value the ESPP (Detail) - ESPP purchase rights	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
Class Of Stock [Line Items]
Expected term	1 month 17 days
Expected volatility	34.08%
Expected volatility, minimum		34.08%
Expected volatility, maximum		61.00%
Risk-free interest rate	0.06%	0.06%
Dividend yield	0.00%	0.00%
Minimum
Class Of Stock [Line Items]
Expected term		1 month 17 days
Maximum
Class Of Stock [Line Items]
Expected term		7 months 17 days

Convertible Preferred Stock,_14

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Summary of Share-based Compensation Expense by line item in the Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Class Of Stock [Line Items]
Stock-based compensation expense	$ 7,831	$ 620	$ 17,795	$ 1,453
Cost of revenue
Class Of Stock [Line Items]
Stock-based compensation expense	716	38	1,438	94
Cost of revenue | Subscription and other platform
Class Of Stock [Line Items]
Stock-based compensation expense	607	31	1,190	78
Cost of revenue | Professional services
Class Of Stock [Line Items]
Stock-based compensation expense	109	7	248	16
Sales and marketing
Class Of Stock [Line Items]
Stock-based compensation expense	2,364	162	5,627	450
Research and development
Class Of Stock [Line Items]
Stock-based compensation expense	1,235	70	2,879	189
General and administrative
Class Of Stock [Line Items]
Stock-based compensation expense	$ 3,516	$ 350	$ 7,851	$ 720

Convertible Preferred Stock,_15

Convertible Preferred Stock, Stockholders’ Equity (Deficit) and Equity Incentive Plan - Summary of Unrecognized Stock-based Compensation Expense (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2021USD ($)
Outstanding stock options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense	$ 51,527
Weighted-average amortization period	3 years 1 month 9 days
Restricted stock units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense	$ 39,293
Weighted-average amortization period	3 years 5 months 15 days
ESPP purchase rights
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock-based compensation expense	$ 123
Weighted-average amortization period	1 month 17 days

Income Taxes - Schedule of Inco

Income Taxes - Schedule of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Provision for (benefit from) income taxes	$ (32)	$ 31	$ (65)	$ 123

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Increase in benefit from income taxes	$ 0.1	$ 0.2

Net Income (Loss) Per Share A_3

Net Income (Loss) Per Share Attributable to Common Stockholders - Schedule of Computation of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Basic net income (loss) per share
Net income (loss)	$ (9,400)	$ 6,605	$ (14,747)	$ 11,248
Cumulative preferred dividends allocated to preferred stockholders	0	(1,467)	(558)	(4,219)
Net income (loss) attributable to common stockholders	(9,400)	5,138	(15,305)	7,029
Income available to participating securities	0	(3,716)	0	(5,175)
Net income (loss) available to common stockholders	$ (9,400)	$ 1,422	$ (15,305)	$ 1,854
Net income (loss) per share of common stock, basic (in dollars per share)	$ (0.20)	$ 0.14	$ (0.36)	$ 0.19
Weighted-average common stock outstanding, basic (in shares)	47,101,200	10,420,584	42,149,108	9,755,373
Diluted net income (loss) per share
Net income (loss)	$ (9,400)	$ 6,605	$ (14,747)	$ 11,248
Cumulative preferred dividends allocated to preferred stockholders	0	(1,467)	(558)	(4,219)
Net income (loss) attributable to common stockholders	(9,400)	5,138	(15,305)	7,029
Reallocation of earnings to participating securities considering potentially dilutive securities	0	(3,158)	0	(4,709)
Net income (loss) available to common stockholders	$ (9,400)	$ 1,980	$ (15,305)	$ 2,320
Net income (loss) per share of common stock, diluted (in dollars per share)	$ (0.20)	$ 0.12	$ (0.36)	$ 0.17
Weighted-average common stock outstanding, basic (in shares)	47,101,200	10,420,584	42,149,108	9,755,373
Weighted average dilutive effect of stock options and restricted stock (in shares)	0	6,647,513	0	3,662,032
Weighted-average common stock outstanding, diluted (in shares)	47,101,200	17,068,097	42,149,108	13,417,405

Net Income (Loss) Per Share A_4

Net Income (Loss) Per Share Attributable to Common Stockholders - Schedule of Potential Shares of Common Stock Excluded from Computation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total antidilutive securities	12,021,235	5,712,840	12,021,235	5,607,416
Outstanding stock options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total antidilutive securities	10,269,096	168,922	10,269,096	63,498
Restricted stock units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total antidilutive securities	1,655,511	0	1,655,511	0
ESPP purchase rights
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total antidilutive securities	96,628	0	96,628	0
Convertible Preferred Stock (On An If-converted Basis)
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Total antidilutive securities	0	5,543,918	0	5,543,918

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details) - Chief Executive Officer of Third-party Vendor - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Accounts Payable and Accrued Liabilities
Related Party Transaction [Line Items]
Related party transactions, amounts owed	$ 0.2		$ 0.2		$ 0.2
Research and development
Related Party Transaction [Line Items]
Engineering and quality assurance costs	$ 0.7	$ 0.4	$ 1.8	$ 1.2