Upwork (UPWK) 10-Q 7 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 31, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Entity Registrant Name	Upwork Inc.
Entity Central Index Key	0001627475
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Common Stock, Shares Outstanding		110,803,709

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 67,092	$ 129,128
Marketable securities	62,442	0
Funds held in escrow, including funds in transit	118,302	98,186
Trade and client receivables – net of allowance of $2,195 and $2,832 as of June 30, 2019 and December 31, 2018, respectively	51,447	22,315
Prepaid expenses and other current assets	6,554	6,253
Total current assets	305,837	255,882
Property and equipment, net	19,207	10,815
Goodwill	118,219	118,219
Intangible assets, net	4,670	6,004
Other assets, noncurrent	976	653
Total assets	448,909	391,573
Current liabilities
Accounts payable	1,521	2,073
Escrow funds payable	118,302	98,186
Debt, current	32,574	5,671
Accrued expenses and other current liabilities	19,132	20,948
Deferred revenue	1,130	722
Total current liabilities	172,659	127,600
Debt, noncurrent	14,469	18,239
Other liabilities, noncurrent	4,148	1,989
Total liabilities	191,276	147,828
Commitments and contingencies (Note 5)
Stockholders’ equity
Common stock, $0.0001 par value; 490,000,000 shares authorized as of June 30, 2019 and December 31, 2018; 110,708,530 and 106,454,321 shares issued and outstanding as of June 30, 2019 and December 31, 2018, respectively	11	11
Additional paid-in capital	407,876	387,233
Accumulated deficit	(150,254)	(143,499)
Total stockholders' equity	257,633	243,745
Total liabilities and stockholders' equity	$ 448,909	$ 391,573

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 2,195	$ 2,832
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	490,000,000	490,000,000
Common stock, shares issued (in shares)	110,708,530	106,454,321
Common stock, shares outstanding (in shares)	110,708,530	106,454,321

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Revenue	$ 74,256	$ 62,681	$ 143,180	$ 121,899
Cost of revenue	21,588	20,457	42,713	40,074
Gross profit	52,668	42,224	100,467	81,825
Operating expenses
Research and development	15,696	12,812	31,496	26,303
Sales and marketing	24,479	16,414	44,997	36,087
General and administrative	14,113	11,219	29,790	22,395
Provision for transaction losses	855	1,450	1,492	2,720
Total operating expenses	55,143	41,895	107,775	87,505
Income (loss) from operations	(2,475)	329	(7,308)	(5,680)
Interest expense	357	556	730	1,085
Other (income) expense, net	(832)	173	(1,311)	422
Loss before income taxes	(2,000)	(400)	(6,727)	(7,187)
Income tax provision	(27)	(12)	(28)	(9)
Net loss	$ (2,027)	$ (412)	$ (6,755)	$ (7,196)
Net loss per share, basic and diluted (in dollars per share)	$ (0.02)	$ (0.01)	$ (0.06)	$ (0.21)
Weighted-average shares used to compute net loss per share, basic and diluted (in shares)	108,683,099	35,104,769	107,665,492	34,651,331

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCKAND STOCKHOLDERS’ EQUITY (DEFICIT) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Redeemable Convertible Preferred Stock (in shares)	61,279,079
Redeemable Convertible Preferred Stock	$ 166,486
Beginning balance (in shares) at Dec. 31, 2017		33,740,323
Beginning balance at Dec. 31, 2017	(31,367)	$ 3	$ 92,222	$ (123,592)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		2,139,680
Issuance of common stock upon exercise of stock options and common stock warrants	4,271	$ 1	4,270
Stock-based compensation expense	3,681		3,681
Net loss	(7,196)			(7,196)
Ending balance (in shares) at Jun. 30, 2018		35,880,003
Ending balance at Jun. 30, 2018	$ (30,611)	$ 4	100,173	(130,788)
Redeemable Convertible Preferred Stock (in shares)	61,279,079
Redeemable Convertible Preferred Stock	$ 166,486
Beginning balance (in shares) at Mar. 31, 2018		34,654,360
Beginning balance at Mar. 31, 2018	(35,045)	$ 4	95,327	(130,376)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		1,225,643
Issuance of common stock upon exercise of stock options and common stock warrants	3,053		3,053
Stock-based compensation expense	1,793		1,793
Net loss	(412)			(412)
Ending balance (in shares) at Jun. 30, 2018		35,880,003
Ending balance at Jun. 30, 2018	$ (30,611)	$ 4	100,173	(130,788)
Redeemable Convertible Preferred Stock (in shares)	61,279,079
Redeemable Convertible Preferred Stock	$ 166,486
Redeemable Convertible Preferred Stock (in shares)	0
Redeemable Convertible Preferred Stock	$ 0
Beginning balance (in shares) at Dec. 31, 2018		106,454,321
Beginning balance at Dec. 31, 2018	$ 243,745	$ 11	387,233	(143,499)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)	3,584,854	3,918,539
Issuance of common stock upon exercise of stock options and common stock warrants	$ 10,350		10,350
Stock-based compensation expense	6,716		6,716
Issuance of common stock for settlement of RSUs (in shares)		55,362
Issuance of common stock in connection with employee stock purchase plan (in shares)		280,308
Issuance of common stock in connection with employee stock purchase plan	3,577		3,577
Net loss	(6,755)			(6,755)
Ending balance (in shares) at Jun. 30, 2019		110,708,530
Ending balance at Jun. 30, 2019	$ 257,633	$ 11	407,876	(150,254)
Redeemable Convertible Preferred Stock (in shares)	0
Redeemable Convertible Preferred Stock	$ 0
Beginning balance (in shares) at Mar. 31, 2019		106,729,758
Beginning balance at Mar. 31, 2019	243,972	$ 11	392,188	(148,227)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		3,645,434
Issuance of common stock upon exercise of stock options and common stock warrants	9,583		9,583
Stock-based compensation expense	2,528		2,528
Issuance of common stock for settlement of RSUs (in shares)		53,030
Issuance of common stock in connection with employee stock purchase plan (in shares)		280,308
Issuance of common stock in connection with employee stock purchase plan	3,577		3,577
Net loss	(2,027)			(2,027)
Ending balance (in shares) at Jun. 30, 2019		110,708,530
Ending balance at Jun. 30, 2019	$ 257,633	$ 11	$ 407,876	$ (150,254)
Redeemable Convertible Preferred Stock (in shares)	0
Redeemable Convertible Preferred Stock	$ 0

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (6,755)	$ (7,196)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Provision for transaction losses	1,038	2,720
Depreciation and amortization	2,827	2,255
Amortization of debt issuance costs	26	51
Amortization of discount on purchases of marketable securities	(665)	0
Change in fair value of redeemable convertible preferred stock warrant liability	0	359
Change in fair value of Tides Foundation common stock warrant	377	0
Stock-based compensation expense	6,926	3,681
Loss on disposal of fixed assets	0	33
Changes in operating assets and liabilities:
Trade and client receivables	(30,288)	(8,620)
Prepaid expenses and other assets	(701)	(572)
Accounts payable	(589)	261
Accrued expenses and other liabilities	(430)	17,333
Deferred revenue	408	98
Net cash provided by (used in) operating activities	(27,826)	10,403
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of marketable securities	(86,567)	0
Sale of marketable securities	24,800	0
Decrease (increase) in restricted cash	150	(100)
Purchases of property and equipment	(7,435)	(1,297)
Internal-use software and platform development costs	(2,182)	(1,945)
Net cash used in investing activities	(71,234)	(3,342)
CASH FLOWS FROM FINANCING ACTIVITIES:
Changes in funds held in escrow, including funds in transit	(20,116)	5,694
Changes in escrow funds payable	20,116	(5,694)
Proceeds from exercises of stock options and common stock warrants	10,340	4,271
Proceeds from borrowings on debt	50,000	0
Repayment of debt	(26,893)	0
Proceeds from employee stock purchase plan	3,577	0
Payments of costs related to the initial public offering	0	(1,596)
Net cash provided by financing activities	37,024	2,675
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(62,036)	9,736
Cash and cash equivalents, beginning of period	129,128	21,595
Cash and cash equivalents, end of period	67,092	31,331
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for interest	714	1,053
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Property and equipment purchased but not yet paid	3,140	355
Unpaid deferred offering costs	$ 0	$ 1,505

Organization and Description of

Organization and Description of Business	6 Months Ended
	Jun. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business Upwork Inc. (the “Company” or “Upwork”) operates an online marketplace that enables businesses (“clients”) to find and work with highly-skilled independent professionals (“freelancers,” and, together with clients, “users”). The Company was originally incorporated in the state of Delaware in December 2013 prior to and in connection with the combination (the “Elance-oDesk Combination”) of Elance, Inc. (“Elance”) and oDesk Corporation (“oDesk”). The Company changed its name to Elance-oDesk, Inc. shortly before the Elance-oDesk Combination in March 2014, and later to Upwork Inc. in May 2015. In 2015, the Company relaunched as Upwork and commenced consolidation of its two operating platforms. In 2016, following completion of the platform consolidation, the Company began operating under a single platform. The Company is currently headquartered in Santa Clara, California. Unless otherwise expressly stated or the context otherwise requires, the terms “Upwork” and the “Company” in these notes to the condensed consolidated financial statements refer to Upwork and its wholly-owned subsidiaries. Initial Public Offering In October 2018, the Company completed its initial public offering (“IPO”), in which the Company issued and sold an aggregate of 7,840,908 of the Company’s common stock, including 1,022,727 shares pursuant to the exercise of the underwriters’ option to purchase additional shares. The shares were sold to the underwriters at the IPO price of $15.00 per share less an underwriting discount of $1.05 per share. The Company received aggregate net proceeds of $109.4 million from the IPO after deducting underwriting discounts and commissions but before deducting offering expenses payable by the Company.

Basis of Presentation and Summa

Basis of Presentation and Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation and Summary of Significant Accounting Policies	Basis of Presentation and Summary of Significant Accounting Policies Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) and applicable rules and regulations of the SEC regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this Quarterly Report should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 (the “Annual Report”), filed with the SEC on March 7, 2019. The condensed consolidated balance sheet as of December 31, 2018 included herein was derived from the audited financial statements as of that date, but does not include all disclosures including notes required by U.S. GAAP. The condensed consolidated financial statements include the accounts of Upwork Inc. and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated. The accompanying condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, changes in stockholders’ equity and cash flows for the interim periods, but do not purport to be indicative of the results of operations or financial condition to be anticipated for the full year ending December 31, 2019. Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make certain estimates, judgments, and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the periods presented. Such estimates include, but are not limited to: the useful lives of assets; assessment of the recoverability of long-lived assets; goodwill impairment; allowance for doubtful accounts; liabilities relating to transaction losses; the valuation of warrants; stock-based compensation; and accounting for income taxes. Management bases its estimates on historical experience and on various other assumptions that management believes to be reasonable under the circumstances. The Company evaluates its estimates, assumptions, and judgments on an ongoing basis using historical experience and other factors and revises them when facts and circumstances dictate. Actual results could materially differ from these estimates. Significant Accounting Policies The significant accounting policies applied in the Company’s audited consolidated financial statements, as disclosed in the Annual Report, are applied consistently in these unaudited interim condensed consolidated financial statements, except as noted below. Marketable Securities Beginning in 2019, the Company purchased various short-term, marketable securities consisting of commercial paper, treasury bills, and U.S. government securities, all of which have contractual maturities within 12 months from the date of purchase and are classified as available-for-sale marketable securities. These marketable securities are carried at estimated fair value with unrealized gains and losses, net of taxes, included within the stockholders’ equity section of the Company’s condensed consolidated balance sheet. The Company periodically reviews its available-for-sale marketable securities for other-than-temporary impairments. The Company considers factors such as the duration, severity, and the reason for any decline in value, the potential recovery period, and its intent to sell. For debt securities, the Company also considers whether (i) it is more likely than not that the Company will be required to sell the debt securities before recovery of their amortized cost basis and (ii) the amortized cost basis cannot be recovered as a result of credit losses. Unrealized losses are charged against other (income) expense, net when a decline in fair value is determined to be other-than-temporary. The Company determines realized gains or losses from the sale of marketable securities on a specific identification method and records such gains or losses as other (income) expense, net within the Company’s condensed consolidated statements of operations. Income Taxes The Company’s income tax provision for interim periods is determined using an estimate of the Company’s annual effective tax rate, adjusted for discrete items arising in the quarter. The Company’s effective tax rate differs from the U.S. statutory tax rate primarily due to valuation allowances on the deferred tax assets as it is more likely than not that some, or all, of the Company’s deferred tax assets will not be realized. The Company continues to maintain a full valuation allowance against its net deferred tax assets. Due to tax losses and the offsetting valuation allowance, the income tax provision for the three and six months ended June 30, 2019 and 2018, respectively, was immaterial to the Company’s condensed consolidated financial statements. Recent Accounting Pronouncements Not Yet Adopted As an emerging growth company (“EGC”), the Company is permitted by the Jumpstart Our Business Startups Act (the “JOBS Act”) to delay adoption of new or revised accounting pronouncements applicable to public companies until such pronouncements are made applicable to private companies. The Company has elected to use this extended transition period under the JOBS Act. As a result, so long as it remains an EGC, the Company’s financial statements may not be comparable to the financial statements of issuers that are required to comply with the effective dates for new or revised accounting standards that are applicable to public companies. Effective as of December 31, 2019, the Company will cease to qualify as an EGC. As a result, the Company will be required to comply with the requirements for adoption of new or revised accounting pronouncements applicable to public companies. Specifically, the Company will be required to accelerate the adoption of certain accounting standards previously disclosed in its Annual Report as follows: Accounting Pronouncement Previously Disclosed Effective Date Accelerated Effective Date 2017-04, Intangibles — Goodwill and Others (Topic 350): Simplifying the Test for Goodwill Impairment For the year ending December 31, 2021 For the year ending December 31, 2020 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities Fiscal years beginning after December 15, 2019 Fiscal years beginning after December 15, 2018 2018-07, Compensation — Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting Fiscal year ending on December 31, 2020 Fiscal year ending on December 31, 2019 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework — Changes to the Disclosure Requirements for Fair Value Measurement Fiscal year ending on December 31, 2021 Fiscal year ending on December 31, 2020 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 Fiscal year ending on December 31, 2021 Fiscal year ending on December 31, 2020 In May 2014, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers . Accounting Standards Codification 606— Revenue from Contracts with Customers (“ASC 606”) supersedes the revenue recognition requirements in ASC 605— Revenue Recognition , and requires the recognition of revenue when promised goods or services are transferred to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASC 606 also includes Subtopic 340-40, Other Assets and Deferred Costs — Contracts with Customers (“Subtopic 340-40” and together with ASC 606, the “new revenue standard”), which requires the deferral of incremental costs of obtaining a contract with a customer. In August 2015, the FASB deferred the effective date for annual reporting periods beginning after December 15, 2017. In 2016, the FASB issued amendments on this guidance with the same effective date and transition guidance. The new revenue standard may be applied retrospectively to each prior period presented (“full retrospective method”) or retrospectively with the cumulative effect recognized as of the date of adoption (“modified retrospective method”). The Company plans to adopt the new standard for the year ending December 31, 2019 during the fourth quarter of 2019, using the modified retrospective method. Interim reporting under the new standard will not be required until 2020. The Company is continuing to evaluate the potential impact that the implementation of this standard will have on its consolidated financial statements, specifically related to the following items: • identification of performance obligations; • principal agent considerations; • whether costs to obtain a contract with a customer will be capitalized or expensed, as well as the timing of recording such capitalization or expense; • timing of revenue recognition; and • revenue disclosures which are expected to expand and may require judgment in certain areas. The Company has concluded that the discounts offered under the Company’s tiered pricing program for freelancer service fees will result in a deferral of revenue under ASC 606. However, the Company has not yet determined the potential adjustment amount. The Company currently does not expect significant changes to its systems and processes from the adoption of the new standard. In January 2016, the FASB issued Accounting Standards Update 2016-01, Financial Instruments (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”). ASU 2016-01 makes targeted improvements to GAAP regarding financial instruments. ASU 2016-01 eliminates the requirement to classify investments in equity securities with readily determinable fair values into trading or available-for-sale categories and requires those equity securities to be measured at fair value with changes in fair value recognized in net earnings rather than in other comprehensive income. ASU 2016-01 also revises certain presentation and disclosure requirements. Under ASU 2016-01, accounting for investments in debt securities remains essentially unchanged. The guidance is effective for the Company for fiscal year 2019 and interim periods beginning fiscal year 2020. Early adoption is not permitted. The Company has not yet evaluated the impact of adopting this guidance on its consolidated financial statements and related disclosures. In February 2016, FASB issued ASU No. 2016-02, Leases (Topic 842) , related to how an entity should recognize lease assets and lease liabilities. The guidance specifies that an entity that is a lessee under lease agreements should recognize lease assets and lease liabilities for those leases classified as operating leases under previous FASB guidance. Accounting for leases by lessors is largely unchanged under the new guidance. In 2018, the FASB also approved an amendment that would permit the option to adopt the new standard prospectively as of the effective date, without adjusting comparative periods presented. Since the Company will no longer qualify as an EGC as of December 31, 2019, it expects to adopt the new lease standard for its annual results for the period ending December 31, 2019. The Company anticipates the effect of adopting this update will be recognizing right-of-use assets and corresponding lease liabilities for leases where the Company is the lessee, primarily comprised of leases for facilities. The Company is currently evaluating the impact to its condensed consolidated financial statements and related disclosures but expects the adoption of this standard to have a material impact on assets and liabilities related to leases. In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326) . The standard changes the methodology for measuring credit losses on financial instruments and the timing of when such losses are recorded. In April 2019, the FASB issued ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments . The amendments in this update represent changes to clarify, correct errors in, or improve the Codification. In May 2019, the FASB issued 2019-05, Financial Instruments—Credit Losses (Topic 326) . The amendments in this update provide entities that have certain instruments within the scope of Subtopic 326-20, Financial Instruments—Credit Losses—Measured at Amortized Cost , with an option to irrevocably elect the fair value option in Subtopic 825-10, Financial Instruments—Overall , applied on an instrument-by-instrument basis for eligible instruments, upon adoption of Topic 326 . The guidance is effective for the Company for fiscal year 2020 with early adoption permitted. The standard requires a modified retrospective method of adoption. The Company has not yet evaluated the impact of these standard updates on its consolidated financial statements and related disclosures.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company defines fair value as the exchange price that would be received from the sale of an asset or paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance describes three levels of inputs that may be used to measure fair value: • Level I—Observable inputs that reflect unadjusted quoted prices for identical assets or liabilities in active markets; • Level II—Observable inputs other than Level I prices, such as unadjusted quoted prices for similar assets or liabilities in active markets, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and • Level III—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. These inputs are based on the Company’s own assumptions used to measure assets and liabilities at fair value and require significant management judgment or estimation. The categorization of a financial instrument within the fair value hierarchy is based upon the lowest level of input that is significant to its fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the assets or liability. The Company’s financial instruments that are carried at fair value consist of Level I and Level II assets as of June 30, 2019 and December 31, 2018. The following tables set forth the fair value of the Company’s financial assets measured at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): June 30, 2019 Level I Level II Level III Total Cash equivalents Money market funds $ 51,169 $ — $ — $ 51,169 Commercial paper — 2,498 — 2,498 Marketable securities Commercial paper — 42,481 — 42,481 Treasury bills 4,991 — — 4,991 U.S. government securities 14,970 — — 14,970 Total financial assets $ 71,130 $ 44,979 $ — $ 116,109 December 31, 2018 Level I Level II Level III Total Cash equivalents—money market funds $ 117,138 $ — $ — $ 117,138 Total financial assets $ 117,138 $ — $ — $ 117,138 Prior to the IPO, the Company measured its redeemable convertible preferred stock warrant liability at fair value on a recurring basis, and it was classified within Level III because the warrants were valued using a Black-Scholes valuation model, for which some inputs were unobservable in the market. For the three and six months ended June 30, 2018, the Company recorded $0.1 million and $0.4 million , respectively, related to the revaluation of its redeemable convertible preferred stock warrant liability, which is included in other (income) expense, net in the Company’s condensed consolidated statement of operations. Upon the closing of the IPO in October 2018, the redeemable convertible preferred stock warrant converted to a common stock warrant. As such, the Company reclassified its redeemable convertible preferred stock warrant liability to additional paid-in capital.

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Jun. 30, 2019
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Balance Sheet Components Cash and Cash Equivalents Cash and cash equivalents consisted of the following (in thousands): June 30, 2019 December 31, 2018 Cash $ 13,425 $ 11,990 Money market funds 51,169 117,138 Commercial paper 2,498 — Total cash and cash equivalents $ 67,092 $ 129,128 Marketable Securities Marketable securities consisted of the following (in thousands): June 30, 2019 Commercial paper $ 42,481 Treasury bills 4,991 U.S. government securities 14,970 Total marketable securities $ 62,442 For the three and six months ended June 30, 2019, the gross unrealized gains and losses on the Company’s marketable securities were immaterial. As of June 30, 2019, the Company considered any decreases in market value to be temporary in nature and did not consider any of the Company’s marketable securities to be other-than-temporarily impaired. As such, the Company did not record any impairment charges with respect to its marketable securities during the three and six months ended June 30, 2019. Property and Equipment, Net Property and equipment, net consisted of the following (in thousands): June 30, 2019 December 31, 2018 Computer equipment and software $ 3,750 $ 3,189 Internal-use software and platform development 8,820 6,287 Leasehold improvements 10,433 5,783 Office furniture and fixtures 2,291 2,545 Total property and equipment 25,294 17,804 Less: accumulated depreciation (6,087 ) (6,989 ) Property and equipment, net $ 19,207 $ 10,815 For the three months ended June 30, 2019 and 2018 , depreciation expense related to property and equipment was $0.6 million and $0.5 million , respectively. For the six months ended June 30, 2019 and 2018 , depreciation expense related to property and equipment was $1.4 million and $0.9 million , respectively. For the three months ended June 30, 2019 and 2018, the Company capitalized $1.4 million and $1.3 million of internal-use software and platform development costs, respectively. For the six months ended June 30, 2019 and 2018, the Company capitalized $2.5 million and $1.9 million of internal-use software and platform development costs, respectively. Amortization expense related to the capitalized internal-use software and platform development costs was immaterial for the three and six months ended June 30, 2019. For the three and six months ended June 30, 2018, there was no amortization expense related to the internal-use software and platform development costs as the underlying assets had not been placed into service as of June 30, 2018. Intangible Assets, Net All of the Company’s identifiable intangible assets were acquired in March 2014 from the Elance-oDesk Combination. Intangible assets, net consisted of the following (in thousands): June 30, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Trade names $ 2,293 $ 2,293 $ — User relationships 18,678 14,008 4,670 Developed technology 10,356 10,356 — Domain names 529 529 — Total $ 31,856 $ 27,186 $ 4,670 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Trade names $ 2,293 $ 2,293 $ — User relationships 18,678 12,674 6,004 Developed technology 10,356 10,356 — Domain names 529 529 — Total $ 31,856 $ 25,852 $ 6,004 For each of the three and six months ended June 30, 2019 and 2018, amortization expense of intangible assets was $0.7 million and $1.3 million , respectively. Amortization expense is included in general and administrative expenses. As of June 30, 2019 , the remaining useful life for user relationships was 1.8 years . As of December 31, 2018 , the remaining useful life for user relationships was 2.3 years . As of June 30, 2019 , the estimated future amortization expense for the acquired intangible assets was as follows (in thousands): June 30, 2019 Remainder of 2019 $ 1,334 2020 2,668 2021 668 Total estimated future amortization expense $ 4,670 Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following (in thousands): June 30, 2019 December 31, 2018 Accrued compensation and related benefits $ 3,712 $ 9,314 Accrued freelancer costs 799 2,465 Accrued indirect taxes 2,192 1,630 Accrued vendor expenses 11,150 6,002 Accrued payment processing fees 776 715 Other 503 822 Total accrued expenses and other current liabilities $ 19,132 $ 20,948

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Leases The Company leases office space under five non-cancellable operating lease agreements, which expire from 2019 through 2028. The terms of the office leases contain rent escalation clauses, rent holidays, and/or tenant improvement allowances. The Company recognizes rent expense on a straight-line basis over the non-cancellable lease term and records the difference between cash payments and the recognition of rent expense as a deferred rent liability. Where leases contain escalation clauses, rent holidays, and/or tenant improvement allowances, the Company applies them in the determination of straight-line rent expense over the lease term. In February 2019, the Company entered into an agreement for a non-cancellable operating lease for new office space in Santa Clara, California. From June 1, 2019 through October 15, 2028, total minimum lease payments under the lease agreement are $14.3 million , with lease payments ranging from $1.4 million to $1.8 million per year. The Company took possession of the Santa Clara office space for its corporate headquarters during the first quarter of 2019 and moved its corporate headquarters and related operations in the second quarter of 2019 shortly after the termination of its Mountain View, California office lease. As a result, the Company accelerated the depreciation expense of its leasehold improvements and furniture and fixtures on the cease-use date for the space exited in May 2019, which was immaterial for the three and six months ended June 30, 2019. In 2018, the Company entered into an agreement to extend its non-cancellable operating lease for its San Francisco office through 2024. From September 1, 2019 through August 31, 2024, total minimum lease payments under the lease agreement are $15.7 million , with lease payments ranging from $1.0 million to $2.2 million per year from 2019 to 2024. Also in 2018, the Company entered into an agreement for a non-cancellable operating lease for new office space in Chicago through October 2024. In December 2018, the Company amended this agreement (the “First Amendment”) to extend the term of the original lease from October 2024 to April 2025 and to lease additional office space to accommodate continued headcount growth. From June 1, 2019 through April 30, 2025, total minimum lease payments under the original lease agreement and the First Amendment are $10.3 million , with lease payments ranging from $0.5 million to $2.0 million per year from 2019 to 2025. The Company moved its Chicago-based operations to this new office space in January 2019. In connection with this move, the Company entered into two sublease agreements that provided for the sublease of the two office spaces the Company occupied prior to its execution of the new operating lease. The Company exited the two spaces in December 2018 and January 2019, respectively. As a result, the Company accelerated the depreciation expense of its leasehold improvements and furniture and fixtures on the cease-use date for the space exited in January 2019 and accordingly recorded $0.3 million of accelerated depreciation expense during the three months ended March 31, 2019. The expected sublease income from the two sublease agreements is reflected in the future aggregate minimum lease payment table below. As of June 30, 2019, future aggregate minimum lease payments under the non-cancellable operating leases, net of sublease income, were as follows (in thousands): June 30, 2019 Remainder of 2019 $ 1,722 2020 5,921 2021 6,405 2022 6,588 2023 6,776 Thereafter 13,137 Less: sublease income (656 ) Total $ 39,893 For the three months ended June 30, 2019 and 2018, rent expense was $1.5 million and $0.9 million , respectively. For the six months ended June 30, 2019 and 2018, rent expense was $2.7 million and $1.9 million , respectively. Letters of Credit In conjunction with the operating lease agreements, as of June 30, 2019 and December 31, 2018, the Company had four and three irrevocable letters of credit outstanding, respectively, in the aggregate amount of $1.1 million and $0.8 million , respectively. The letters of credit are collateralized by restricted cash in the same respective amounts and begin to expire in 2019. No amounts had been drawn against these letters of credit as of June 30, 2019 and December 31, 2018. Contingencies The Company accrues contingent liabilities when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. From time to time in the normal course of business, various claims and litigation have been asserted or commenced. Due to uncertainties inherent in litigation and other claims the Company can give no assurance that it will prevail in any such matters, which could subject the Company to significant liability or damages. Any claims or litigation could have an adverse effect on the Company’s business, financial position, results of operations, or cash flows in or following the period that claims or litigation are resolved. As of June 30, 2019 and December 31, 2018 , the Company was not a party to any material legal proceedings or claims, nor is the Company aware of any pending or threatened litigation or claims that could reasonably be expected to have a material adverse effect on its business, operating results, cash flows, or financial condition. Accordingly, the Company has determined that the existence of a material loss as of this date is neither probable nor reasonably possible. Indemnification The Company has indemnification agreements with its officers, directors, and certain key employees to indemnify them while they are serving in good faith in their respective positions. In the ordinary course of business, the Company enters into contractual arrangements under which it agrees to provide indemnification of varying scope and terms to vendors and other parties, including, but not limited to, losses arising out of the Company’s breach of such agreements. In addition, subject to the terms of the applicable agreement, as part of the Company’s Upwork Enterprise offering, the Company indemnifies clients that subscribe to worker classification services for losses arising from worker misclassification and intellectual property claims made by third parties relating to the use of the Company’s platform. The Company also indemnifies clients utilizing its Upwork Business offering for losses arising from intellectual property claims made by third parties relating to the use of the Company’s platform, subject to the terms of the applicable agreement. It is not possible to determine the maximum potential loss under these indemnification provisions due to the Company’s limited history of prior indemnification claims and the facts and circumstances involved in each particular provision.

Debt

Debt	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Debt	Debt The following table presents the carrying value of the Company’s debt obligations as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 First Term Loan—18 months of interest-only payments ended in March 2019 followed by 36 equal monthly installments of principal plus interest, maturing March 2022; interest at prime plus 0.25% per annum $ 13,750 $ 15,000 Second Term Loan—11 months of interest-only payments ended in October 2018 followed by 47 equal monthly installments of principal plus interest, maturing September 2022. As of September 30, 2018, the Company achieved trailing six-month EBITDA of at least $1.0 million; as a result, the interest-only repayment period extended to March 2019, followed by 42 equal monthly installments of principal plus interest; bears interest at prime plus 5.25% per annum. As a result of the IPO, the interest rate was reduced to prime plus 0.25% per annum in the fourth quarter of 2018 8,357 9,000 Line of credit—interest at prime with accrued interest due monthly; matures September 2020 25,000 — Total debt 47,107 24,000 Less: unamortized debt discount issuance costs (64 ) (90 ) Balance 47,043 23,910 Debt, current (32,574 ) (5,671 ) Debt, noncurrent $ 14,469 $ 18,239 Weighted-average interest rate 5.96 % 6.89 % Under the Company’s Loan and Security Agreement, as amended (the “Loan Agreement”), the aggregate amount of the facility was up to $49.0 million , consisting of a term loan in the original principal amount of $15.0 million (the “First Term Loan”), a term loan in the original principal amount of $9.0 million (the “Second Term Loan” and, together with the First Term Loan, the “Term Loans”) and a revolving line of credit, which permits borrowings of up to $25.0 million subject to customary conditions. Among other things, the Company may only borrow funds under the revolving line of credit if, after giving effect thereto, total borrowings under the line of credit do not exceed a specified percentage of eligible trade and client accounts receivable. In September 2018, the Company entered into a second amendment (the “Second Amendment”) to the Loan Agreement, which expanded the types of eligible trade and client accounts receivable considered for the determination of the borrowing base of the revolving line of credit. The Second Amendment also provided for a reduction in the interest rate for the Second Term Loan, from the prime rate plus 5.25% per annum to the prime rate plus 0.25% per annum, from and after the occurrence of an initial public offering by the Company with net proceeds of more than $50.0 million . This reduction became effective following the completion of the IPO in October 2018. In March 2019, the Company entered into a third amendment (the “Third Amendment”) to the Loan Agreement, which, among other changes, (i) amended the adjusted quick ratio financial covenant to provide that the Company will maintain an adjusted quick ratio of 1.75 to 1.00 (previously 1.30 to 1.00), (ii) reduced the frequency with which the Company is required to provide certain financial information to the lender during periods in which it maintains an adjusted quick ratio of 2.50 to 1.00, and (iii) eliminated the minimum EBITDA covenant with which the Company was required to comply. The Company was in compliance with its covenants under the Loan Agreement as of June 30, 2019 and December 31, 2018. To the extent the Company has not yet collected funds for hourly billings from clients that are in-transit due to timing differences in receipt of cash from clients, the Company may utilize the revolving line of credit to satisfy customary escrow funding requirements. The Company drew down $25.0 million under the revolving line of credit for such purpose in each of March and June 2019, which the Company subsequently repaid in April and July 2019, respectively. See “Note 14—Subsequent Events.” Pursuant to the terms of the Loan Agreement, in April 2019, the Company commenced repayment on the Term Loans. During the three months ended June 30, 2019, the Company repaid $1.3 million related to the First Term Loan and $0.6 million related to the Second Term Loan. Amortization expense related to the debt discount was immaterial for the three and six months ended June 30, 2019 and 2018 .

Redeemable Convertible Preferre

Redeemable Convertible Preferred Stock	6 Months Ended
	Jun. 30, 2019
Temporary Equity Disclosure [Abstract]
Redeemable Convertible Preferred Stock	Redeemable Convertible Preferred Stock Prior to the IPO, the Company financed its operations and capital expenditures primarily through sales of convertible preferred stock, bank borrowings, and utilization of cash generated from operations in the periods in which the Company generated cash flows from operations. As a result of the IPO, all of the Company’s 61,279,079 shares of then-outstanding redeemable convertible preferred stock automatically converted into shares of common stock on a one -for-one basis. Therefore, there were no issued or outstanding shares of redeemable convertible preferred stock as of June 30, 2019 and December 31, 2018.

Preferred and Common Stock Warr

Preferred and Common Stock Warrants	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Preferred and Common Stock Warrants	Preferred and Common Stock Warrants Redeemable Convertible Preferred Stock Warrants As a result of the Elance-oDesk Combination, a redeemable convertible preferred stock warrant that was originally issued by Elance prior to the Elance-oDesk Combination became exercisable to purchase up to 124,506 and 273,825 shares of the Company’s Series A-1 and Series A-2 redeemable convertible preferred stock, respectively, at an exercise price of $3.13 per share. Prior to the IPO, the Company estimated the fair value of its redeemable convertible preferred stock warrant using the Black-Scholes valuation model. For the three and six months ended June 30, 2018, the Company recorded $0.1 million and $0.4 million , respectively, related to the revaluation of its redeemable convertible preferred stock warrant liability, which is included in other (income) expense, net in the Company’s condensed consolidated statement of operations. Upon completion of the IPO, this warrant converted to a common stock warrant exercisable for the same number of shares and was reclassified to additional paid-in capital. The common stock warrant was outstanding and exercisable as of December 31, 2018. In April 2019, this common stock warrant was exercised in full at a total cost of $1.2 million . In lieu of a cash payment, the holder of the warrant surrendered 64,646 shares of common stock to cover the exercise price. The Company issued 333,685 shares of common stock upon the exercise of this common stock warrant. Common Stock Warrant In 2018, the Company established The Upwork Foundation initiative. The program includes a donor-advised fund created through the Tides Foundation. In May 2018, the Company issued a warrant to purchase 500,000 shares of its common stock at an exercise price of $0.01 per share to the Tides Foundation. The vesting and exercisability provisions of the warrant became effective upon the IPO in October 2018. This warrant is exercisable as to 1/10 th of the shares on each anniversary of the IPO, with proceeds from the sale of such shares to be donated in accordance with the Company’s directive. For the three and six months ended June 30, 2019, the Company recorded $0.2 million and $0.4 million of expense, respectively, related to the revaluation of this warrant, which is included in general and administrative expense in the Company’s condensed consolidated statement of operations.

Common Stock

Common Stock	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Common Stock	Common Stock Holders of common stock are entitled to one vote per share and are entitled to receive dividends, if any, on a pro rata basis whenever funds are legally available and when, as, and if declared by the Company’s board of directors. As of June 30, 2019 and December 31, 2018 , the Company was authorized to issue 490,000,000 shares of common stock. As of June 30, 2019 and December 31, 2018 , the Company had reserved shares of common stock for future issuance as follows: June 30, 2019 December 31, 2018 Options issued and outstanding 19,771,277 23,774,279 RSUs issued and outstanding 1,213,337 288,460 Warrant to purchase common stock 500,000 898,331 Remaining shares reserved for future issuances under 2018 Equity Incentive Plan 15,320,498 10,558,306 Remaining shares reserved for futures issuances under 2018 Employee Stock Purchase Plan 2,271,326 1,700,000 Total 39,076,438 37,219,376

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation Equity Incentive Plans The following table summarizes activity under the Company’s stock option plans: Number of Shares Underlying Outstanding Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Balances at December 31, 2018 23,774,279 $ 3.71 7.10 $ 342,262 Exercised (3,584,854 ) 2.89 Forfeited and canceled (418,148 ) 4.78 Balances at June 30, 2019 19,771,277 $ 3.84 6.81 $ 241,977 In 2018, the Company’s board of directors and stockholders each adopted the 2018 Equity Incentive Plan (the “2018 EIP”), which became effective on the date immediately prior to the date of the IPO. Awards granted under the 2018 EIP may be (i) incentive stock options, (ii) nonqualified stock options, (iii) restricted stock units (“RSUs”), (iv) restricted stock awards, or (v) stock appreciation rights, as determined by the Company’s board of directors at the time of grant. The following table summarizes the RSU activity and related information under the 2018 EIP: Number of RSUs Outstanding Weighted-Average Grant Date Fair Value Unvested balance at December 31, 2018 288,460 $ 15.00 Granted 1,025,786 19.16 Vested (55,362 ) 15.30 Forfeited and canceled (45,547 ) 18.22 Unvested balance at June 30, 2019 1,213,337 $ 18.38 Pursuant to the terms of the 2018 EIP, in January 2019, the number of shares available for grant was increased by 5,322,716 shares. In July 2018, the Company’s board of directors granted an option exercisable for up to 1,860,000 shares of common stock to the Company’s Chief Executive Officer under the 2018 EIP (the “CEO Award”). The vesting and exercisability of the CEO Award is contingent upon the recipient’s continuous service as the Chief Executive Officer and the achievement of certain measurement objectives during three separate measurement periods within the period of time beginning on January 1, 2019 and ending on December 31, 2023. Each reporting period, the Company assesses the probability that the performance criteria will be met and records expense for those shares that are probable of vesting. As of June 30, 2019, the Company determined that vesting of the CEO Award was not probable. As a result, the Company reversed the full amount of previously recorded expense related to the CEO Award, which amounted to $1.4 million and $0.9 million for the three and six months ended June 30, 2019, respectively. In February 2019, the Company’s board of directors approved the omnibus Performance Bonus Plan along with the performance criteria and bonus pool for 2019 (the “Bonus Plan”), which provides for the payment of bonus compensation to selected employees of the Company, including the Company’s executive officers, upon the achievement of certain performance criteria. In lieu of a cash payment, bonus payments to certain of the Company’s management team will be paid in the form of fully vested RSUs issued from the 2018 EIP. The ultimate number of fully vested RSUs to be granted will be determined by dividing (A) the total dollar value of the bonus that would be delivered in cash by (B) the closing stock price on the day prior to the award grant date, which is expected to occur in the first quarter of 2020. The payment of the bonus in fully vested RSUs requires accounting as a stock-based award under U.S. GAAP. Because the number of fully vested RSUs to be granted is dependent upon the future closing price of the Company’s common stock, the Company has classified this award as a liability within its condensed consolidated balance sheet as of June 30, 2019. Each reporting period, the Company assesses the probability that the performance criteria will be met and records expense for those shares that are probable of vesting. Employee Stock Purchase Plan In 2018, the Company’s board of directors and stockholders each adopted the 2018 Employee Stock Purchase Plan (the “2018 ESPP”), which became effective upon the completion of the IPO. Pursuant to the terms of the 2018 ESPP, in January 2019, the number of shares of common stock available for issuance was increased by 851,634 shares. During the three months ended June 30, 2019, the Company issued 280,308 shares of common stock under the 2018 ESPP. Stock-Based Compensation The following table summarizes the components of stock-based compensation expense recognized in the condensed consolidated statements of operations (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Cost of revenue $ 73 $ 53 $ 217 $ 105 Research and development 1,686 538 3,066 1,088 Sales and marketing 583 331 1,225 671 General and administrative 289 871 2,418 1,817 Total stock-based compensation $ 2,631 $ 1,793 $ 6,926 $ 3,681 Stock-based compensation expense related to non-employee stock option grants was immaterial for the three and six months ended June 30, 2019 and 2018. The amount of stock-based compensation capitalized to internal-use software and platform development costs for the three and six months ended June 30, 2019 and 2018 was immaterial Prior to the IPO, certain common stockholders (who were employees or former employees of the Company) sold shares of the Company’s common stock in secondary market transactions. In 2018, one such transaction occurred. The incremental value between the sale price and the fair value of the common stock at the date of sale aggregated to an immaterial amount of stock-based compensation expense for the three and six months ended June 30, 2018.

Net Loss per Share

Net Loss per Share	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Net Loss per Share	Net Loss per Share The following table sets forth the computation of the Company’s basic and diluted net loss per share for the periods presented (in thousands, except share and per share data): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Numerator: Net loss $ (2,027 ) $ (412 ) $ (6,755 ) $ (7,196 ) Denominator: Weighted-average shares used to compute net loss per share, basic and diluted 108,683,099 35,104,769 107,665,492 34,651,331 Net loss per share, basic and diluted $ (0.02 ) $ (0.01 ) $ (0.06 ) $ (0.21 ) The following potentially dilutive shares were excluded from the computation of diluted net loss per share because including them would have been anti-dilutive: As of June 30, 2019 2018 Options to purchase common stock 19,771,277 22,932,222 Common stock issuable upon conversion of redeemable convertible preferred stock — 61,279,079 Common stock issuable upon exercise of common stock warrants 500,000 500,000 Common stock issuable upon exercise and redeemable conversion of preferred stock warrants — 398,331 Common stock issuable upon vesting of restricted stock units 1,213,337 — Common stock issuable in connection with employee stock purchase plan 802,389 — Total 22,287,003 85,109,632

Segment and Geographical Inform

Segment and Geographical Information	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Segment and Geographical Information	Segment and Geographical Information The Company operates as one operating and reportable segment for purposes of allocating resources and evaluating financial performance. The following table sets forth total revenue by type of service for the periods presented (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Marketplace $ 66,201 $ 55,454 $ 127,104 $ 107,413 Managed services 8,055 7,227 16,076 14,486 Total revenue $ 74,256 $ 62,681 $ 143,180 $ 121,899 The Company generates its revenue from freelancers and clients. The following table sets forth total revenue by geographic area based on the billing address of its freelancers and clients for the periods presented (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Freelancers United States $ 12,486 $ 9,554 $ 24,374 $ 18,657 India 6,904 6,467 13,534 12,573 Philippines 4,929 4,203 9,506 8,158 Rest of world 22,588 20,159 44,283 39,184 Total freelancers 46,907 40,383 91,697 78,572 Clients United States 21,431 18,187 39,105 33,649 Rest of world 5,918 4,111 12,378 9,678 Total clients 27,349 22,298 51,483 43,327 Total revenue $ 74,256 $ 62,681 $ 143,180 $ 121,899 Substantially all of the Company’s long-lived assets were located in the United States as of June 30, 2019 and December 31, 2018 .

401(k) Plan

401(k) Plan	6 Months Ended
	Jun. 30, 2019
Retirement Benefits [Abstract]
401(k) Plan	401(k) Plan The Company offers the Upwork Retirement Savings Plan (the “Retirement Plan”), a defined contribution plan that allows employees to contribute a portion of their salary, subject to the annual limits. Under the Retirement Plan, eligible employees may defer a portion of their pretax salaries, but not more than the statutory limits. The Retirement Plan provides for a discretionary employer matching contribution. The Company makes matching contributions equal to 50% of each dollar contributed, subject to a maximum contribution of $5,000 annually per participant. The Company’s total expense for the matching contributions was $0.5 million and $0.3 million for the three months ended June 30, 2019 and 2018 , respectively. The Company’s total expense for the matching contributions was $1.4 million and $1.1 million for the six months ended June 30, 2019 and 2018, respectively.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events In July 2019, the Company repaid $25.0 million outstanding under the Company’s line of credit that was drawn down in June in order to satisfy the Company’s escrow funding requirements as of June 30, 2019.

Basis of Presentation and Sum_2

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) and applicable rules and regulations of the SEC regarding interim financial reporting. Certain information and note disclosures normally included in the financial statements prepared in accordance with U.S. GAAP have been condensed or omitted pursuant to such rules and regulations. As such, the information included in this Quarterly Report should be read in conjunction with the consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 (the “Annual Report”), filed with the SEC on March 7, 2019. The condensed consolidated balance sheet as of December 31, 2018 included herein was derived from the audited financial statements as of that date, but does not include all disclosures including notes required by U.S. GAAP. The condensed consolidated financial statements include the accounts of Upwork Inc. and its wholly-owned subsidiaries. All intercompany balances and transactions have been eliminated. The accompanying condensed consolidated financial statements reflect all normal recurring adjustments necessary to present fairly the financial position, results of operations, changes in stockholders’ equity and cash flows for the interim periods, but do not purport to be indicative of the results of operations or financial condition to be anticipated for the full year ending December 31, 2019.
Use of Estimates	Use of Estimates The preparation of the condensed consolidated financial statements in conformity with U.S. GAAP requires management to make certain estimates, judgments, and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenue and expenses during the periods presented. Such estimates include, but are not limited to: the useful lives of assets; assessment of the recoverability of long-lived assets; goodwill impairment; allowance for doubtful accounts; liabilities relating to transaction losses; the valuation of warrants; stock-based compensation; and accounting for income taxes. Management bases its estimates on historical experience and on various other assumptions that management believes to be reasonable under the circumstances. The Company evaluates its estimates, assumptions, and judgments on an ongoing basis using historical experience and other factors and revises them when facts and circumstances dictate. Actual results could materially differ from these estimates.
Marketable Securities	Marketable Securities Beginning in 2019, the Company purchased various short-term, marketable securities consisting of commercial paper, treasury bills, and U.S. government securities, all of which have contractual maturities within 12 months from the date of purchase and are classified as available-for-sale marketable securities. These marketable securities are carried at estimated fair value with unrealized gains and losses, net of taxes, included within the stockholders’ equity section of the Company’s condensed consolidated balance sheet. The Company periodically reviews its available-for-sale marketable securities for other-than-temporary impairments. The Company considers factors such as the duration, severity, and the reason for any decline in value, the potential recovery period, and its intent to sell. For debt securities, the Company also considers whether (i) it is more likely than not that the Company will be required to sell the debt securities before recovery of their amortized cost basis and (ii) the amortized cost basis cannot be recovered as a result of credit losses. Unrealized losses are charged against other (income) expense, net when a decline in fair value is determined to be other-than-temporary. The Company determines realized gains or losses from the sale of marketable securities on a specific identification method and records such gains or losses as other (income) expense, net within the Company’s condensed consolidated statements of operations.
Income Taxes	Income Taxes The Company’s income tax provision for interim periods is determined using an estimate of the Company’s annual effective tax rate, adjusted for discrete items arising in the quarter. The Company’s effective tax rate differs from the U.S. statutory tax rate primarily due to valuation allowances on the deferred tax assets as it is more likely than not that some, or all, of the Company’s deferred tax assets will not be realized. The Company continues to maintain a full valuation allowance against its net deferred tax assets. Due to tax losses and the offsetting valuation allowance, the income tax provision for the three and six months ended June 30, 2019 and 2018, respectively, was immaterial to the Company’s condensed consolidated financial statements.
Recent Accounting Pronouncements Not Yet Adopted	Recent Accounting Pronouncements Not Yet Adopted As an emerging growth company (“EGC”), the Company is permitted by the Jumpstart Our Business Startups Act (the “JOBS Act”) to delay adoption of new or revised accounting pronouncements applicable to public companies until such pronouncements are made applicable to private companies. The Company has elected to use this extended transition period under the JOBS Act. As a result, so long as it remains an EGC, the Company’s financial statements may not be comparable to the financial statements of issuers that are required to comply with the effective dates for new or revised accounting standards that are applicable to public companies. Effective as of December 31, 2019, the Company will cease to qualify as an EGC. As a result, the Company will be required to comply with the requirements for adoption of new or revised accounting pronouncements applicable to public companies. Specifically, the Company will be required to accelerate the adoption of certain accounting standards previously disclosed in its Annual Report as follows: Accounting Pronouncement Previously Disclosed Effective Date Accelerated Effective Date 2017-04, Intangibles — Goodwill and Others (Topic 350): Simplifying the Test for Goodwill Impairment For the year ending December 31, 2021 For the year ending December 31, 2020 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities Fiscal years beginning after December 15, 2019 Fiscal years beginning after December 15, 2018 2018-07, Compensation — Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting Fiscal year ending on December 31, 2020 Fiscal year ending on December 31, 2019 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework — Changes to the Disclosure Requirements for Fair Value Measurement Fiscal year ending on December 31, 2021 Fiscal year ending on December 31, 2020 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 Fiscal year ending on December 31, 2021 Fiscal year ending on December 31, 2020 In May 2014, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers . Accounting Standards Codification 606— Revenue from Contracts with Customers (“ASC 606”) supersedes the revenue recognition requirements in ASC 605— Revenue Recognition , and requires the recognition of revenue when promised goods or services are transferred to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASC 606 also includes Subtopic 340-40, Other Assets and Deferred Costs — Contracts with Customers (“Subtopic 340-40” and together with ASC 606, the “new revenue standard”), which requires the deferral of incremental costs of obtaining a contract with a customer. In August 2015, the FASB deferred the effective date for annual reporting periods beginning after December 15, 2017. In 2016, the FASB issued amendments on this guidance with the same effective date and transition guidance. The new revenue standard may be applied retrospectively to each prior period presented (“full retrospective method”) or retrospectively with the cumulative effect recognized as of the date of adoption (“modified retrospective method”). The Company plans to adopt the new standard for the year ending December 31, 2019 during the fourth quarter of 2019, using the modified retrospective method. Interim reporting under the new standard will not be required until 2020. The Company is continuing to evaluate the potential impact that the implementation of this standard will have on its consolidated financial statements, specifically related to the following items: • identification of performance obligations; • principal agent considerations; • whether costs to obtain a contract with a customer will be capitalized or expensed, as well as the timing of recording such capitalization or expense; • timing of revenue recognition; and • revenue disclosures which are expected to expand and may require judgment in certain areas. The Company has concluded that the discounts offered under the Company’s tiered pricing program for freelancer service fees will result in a deferral of revenue under ASC 606. However, the Company has not yet determined the potential adjustment amount. The Company currently does not expect significant changes to its systems and processes from the adoption of the new standard. In January 2016, the FASB issued Accounting Standards Update 2016-01, Financial Instruments (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities (“ASU 2016-01”). ASU 2016-01 makes targeted improvements to GAAP regarding financial instruments. ASU 2016-01 eliminates the requirement to classify investments in equity securities with readily determinable fair values into trading or available-for-sale categories and requires those equity securities to be measured at fair value with changes in fair value recognized in net earnings rather than in other comprehensive income. ASU 2016-01 also revises certain presentation and disclosure requirements. Under ASU 2016-01, accounting for investments in debt securities remains essentially unchanged. The guidance is effective for the Company for fiscal year 2019 and interim periods beginning fiscal year 2020. Early adoption is not permitted. The Company has not yet evaluated the impact of adopting this guidance on its consolidated financial statements and related disclosures. In February 2016, FASB issued ASU No. 2016-02, Leases (Topic 842) , related to how an entity should recognize lease assets and lease liabilities. The guidance specifies that an entity that is a lessee under lease agreements should recognize lease assets and lease liabilities for those leases classified as operating leases under previous FASB guidance. Accounting for leases by lessors is largely unchanged under the new guidance. In 2018, the FASB also approved an amendment that would permit the option to adopt the new standard prospectively as of the effective date, without adjusting comparative periods presented. Since the Company will no longer qualify as an EGC as of December 31, 2019, it expects to adopt the new lease standard for its annual results for the period ending December 31, 2019. The Company anticipates the effect of adopting this update will be recognizing right-of-use assets and corresponding lease liabilities for leases where the Company is the lessee, primarily comprised of leases for facilities. The Company is currently evaluating the impact to its condensed consolidated financial statements and related disclosures but expects the adoption of this standard to have a material impact on assets and liabilities related to leases. In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326) . The standard changes the methodology for measuring credit losses on financial instruments and the timing of when such losses are recorded. In April 2019, the FASB issued ASU 2019-04, Codification Improvements to Topic 326, Financial Instruments—Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments . The amendments in this update represent changes to clarify, correct errors in, or improve the Codification. In May 2019, the FASB issued 2019-05, Financial Instruments—Credit Losses (Topic 326) . The amendments in this update provide entities that have certain instruments within the scope of Subtopic 326-20, Financial Instruments—Credit Losses—Measured at Amortized Cost , with an option to irrevocably elect the fair value option in Subtopic 825-10, Financial Instruments—Overall , applied on an instrument-by-instrument basis for eligible instruments, upon adoption of Topic 326 . The guidance is effective for the Company for fiscal year 2020 with early adoption permitted. The standard requires a modified retrospective method of adoption. The Company has not yet evaluated the impact of these standard updates on its consolidated financial statements and related disclosures.

Basis of Presentation and Sum_3

Basis of Presentation and Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2019
Accounting Policies [Abstract]
Schedule of New Accounting Pronouncements	Specifically, the Company will be required to accelerate the adoption of certain accounting standards previously disclosed in its Annual Report as follows: Accounting Pronouncement Previously Disclosed Effective Date Accelerated Effective Date 2017-04, Intangibles — Goodwill and Others (Topic 350): Simplifying the Test for Goodwill Impairment For the year ending December 31, 2021 For the year ending December 31, 2020 2017-12, Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities Fiscal years beginning after December 15, 2019 Fiscal years beginning after December 15, 2018 2018-07, Compensation — Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting Fiscal year ending on December 31, 2020 Fiscal year ending on December 31, 2019 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework — Changes to the Disclosure Requirements for Fair Value Measurement Fiscal year ending on December 31, 2021 Fiscal year ending on December 31, 2020 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 Fiscal year ending on December 31, 2021 Fiscal year ending on December 31, 2020

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Financial Liabilities Measured at Fair Value on a Recurring Basis	The following tables set forth the fair value of the Company’s financial assets measured at fair value on a recurring basis based on the three-tier fair value hierarchy (in thousands): June 30, 2019 Level I Level II Level III Total Cash equivalents Money market funds $ 51,169 $ — $ — $ 51,169 Commercial paper — 2,498 — 2,498 Marketable securities Commercial paper — 42,481 — 42,481 Treasury bills 4,991 — — 4,991 U.S. government securities 14,970 — — 14,970 Total financial assets $ 71,130 $ 44,979 $ — $ 116,109 December 31, 2018 Level I Level II Level III Total Cash equivalents—money market funds $ 117,138 $ — $ — $ 117,138 Total financial assets $ 117,138 $ — $ — $ 117,138

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Jun. 30, 2019
Balance Sheet Related Disclosures [Abstract]
Cash and Cash Equivalents	Cash and cash equivalents consisted of the following (in thousands): June 30, 2019 December 31, 2018 Cash $ 13,425 $ 11,990 Money market funds 51,169 117,138 Commercial paper 2,498 — Total cash and cash equivalents $ 67,092 $ 129,128
Marketable Securities	Marketable securities consisted of the following (in thousands): June 30, 2019 Commercial paper $ 42,481 Treasury bills 4,991 U.S. government securities 14,970 Total marketable securities $ 62,442
Property and Equipment, Net	Property and equipment, net consisted of the following (in thousands): June 30, 2019 December 31, 2018 Computer equipment and software $ 3,750 $ 3,189 Internal-use software and platform development 8,820 6,287 Leasehold improvements 10,433 5,783 Office furniture and fixtures 2,291 2,545 Total property and equipment 25,294 17,804 Less: accumulated depreciation (6,087 ) (6,989 ) Property and equipment, net $ 19,207 $ 10,815
Intangible Assets, Net	All of the Company’s identifiable intangible assets were acquired in March 2014 from the Elance-oDesk Combination. Intangible assets, net consisted of the following (in thousands): June 30, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Trade names $ 2,293 $ 2,293 $ — User relationships 18,678 14,008 4,670 Developed technology 10,356 10,356 — Domain names 529 529 — Total $ 31,856 $ 27,186 $ 4,670 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Trade names $ 2,293 $ 2,293 $ — User relationships 18,678 12,674 6,004 Developed technology 10,356 10,356 — Domain names 529 529 — Total $ 31,856 $ 25,852 $ 6,004
Estimated Future Amortization Expense for Acquired Intangible Assets	As of June 30, 2019 , the estimated future amortization expense for the acquired intangible assets was as follows (in thousands): June 30, 2019 Remainder of 2019 $ 1,334 2020 2,668 2021 668 Total estimated future amortization expense $ 4,670
Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following (in thousands): June 30, 2019 December 31, 2018 Accrued compensation and related benefits $ 3,712 $ 9,314 Accrued freelancer costs 799 2,465 Accrued indirect taxes 2,192 1,630 Accrued vendor expenses 11,150 6,002 Accrued payment processing fees 776 715 Other 503 822 Total accrued expenses and other current liabilities $ 19,132 $ 20,948

Commitments and Contingencies (

Commitments and Contingencies (Tables)	6 Months Ended
	Jun. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Aggregate Minimum Lease Payments Under Non-Cancelable Operating Leases	As of June 30, 2019, future aggregate minimum lease payments under the non-cancellable operating leases, net of sublease income, were as follows (in thousands): June 30, 2019 Remainder of 2019 $ 1,722 2020 5,921 2021 6,405 2022 6,588 2023 6,776 Thereafter 13,137 Less: sublease income (656 ) Total $ 39,893

Debt (Tables)

Debt (Tables)	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Summary of Carrying Value of Debt	The following table presents the carrying value of the Company’s debt obligations as of June 30, 2019 and December 31, 2018 (in thousands): June 30, 2019 December 31, 2018 First Term Loan—18 months of interest-only payments ended in March 2019 followed by 36 equal monthly installments of principal plus interest, maturing March 2022; interest at prime plus 0.25% per annum $ 13,750 $ 15,000 Second Term Loan—11 months of interest-only payments ended in October 2018 followed by 47 equal monthly installments of principal plus interest, maturing September 2022. As of September 30, 2018, the Company achieved trailing six-month EBITDA of at least $1.0 million; as a result, the interest-only repayment period extended to March 2019, followed by 42 equal monthly installments of principal plus interest; bears interest at prime plus 5.25% per annum. As a result of the IPO, the interest rate was reduced to prime plus 0.25% per annum in the fourth quarter of 2018 8,357 9,000 Line of credit—interest at prime with accrued interest due monthly; matures September 2020 25,000 — Total debt 47,107 24,000 Less: unamortized debt discount issuance costs (64 ) (90 ) Balance 47,043 23,910 Debt, current (32,574 ) (5,671 ) Debt, noncurrent $ 14,469 $ 18,239 Weighted-average interest rate 5.96 % 6.89 %

Common Stock (Tables)

Common Stock (Tables)	6 Months Ended
	Jun. 30, 2019
Equity [Abstract]
Summary of Common Stock Shares Reserved for Future Issuance	As of June 30, 2019 and December 31, 2018 , the Company had reserved shares of common stock for future issuance as follows: June 30, 2019 December 31, 2018 Options issued and outstanding 19,771,277 23,774,279 RSUs issued and outstanding 1,213,337 288,460 Warrant to purchase common stock 500,000 898,331 Remaining shares reserved for future issuances under 2018 Equity Incentive Plan 15,320,498 10,558,306 Remaining shares reserved for futures issuances under 2018 Employee Stock Purchase Plan 2,271,326 1,700,000 Total 39,076,438 37,219,376

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of Activity under Stock Option Plans	The following table summarizes activity under the Company’s stock option plans: Number of Shares Underlying Outstanding Options Weighted-Average Exercise Price Weighted-Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Balances at December 31, 2018 23,774,279 $ 3.71 7.10 $ 342,262 Exercised (3,584,854 ) 2.89 Forfeited and canceled (418,148 ) 4.78 Balances at June 30, 2019 19,771,277 $ 3.84 6.81 $ 241,977
Summary of Activity under RSU Plans	The following table summarizes the RSU activity and related information under the 2018 EIP: Number of RSUs Outstanding Weighted-Average Grant Date Fair Value Unvested balance at December 31, 2018 288,460 $ 15.00 Granted 1,025,786 19.16 Vested (55,362 ) 15.30 Forfeited and canceled (45,547 ) 18.22 Unvested balance at June 30, 2019 1,213,337 $ 18.38
Summary of Components of Stock-Based Compensation Expense Recognized	The following table summarizes the components of stock-based compensation expense recognized in the condensed consolidated statements of operations (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Cost of revenue $ 73 $ 53 $ 217 $ 105 Research and development 1,686 538 3,066 1,088 Sales and marketing 583 331 1,225 671 General and administrative 289 871 2,418 1,817 Total stock-based compensation $ 2,631 $ 1,793 $ 6,926 $ 3,681

Net Loss per Share (Tables)

Net Loss per Share (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders	The following table sets forth the computation of the Company’s basic and diluted net loss per share for the periods presented (in thousands, except share and per share data): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Numerator: Net loss $ (2,027 ) $ (412 ) $ (6,755 ) $ (7,196 ) Denominator: Weighted-average shares used to compute net loss per share, basic and diluted 108,683,099 35,104,769 107,665,492 34,651,331 Net loss per share, basic and diluted $ (0.02 ) $ (0.01 ) $ (0.06 ) $ (0.21 )
Schedule of Potentially Dilutive Shares Excluded from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders	The following potentially dilutive shares were excluded from the computation of diluted net loss per share because including them would have been anti-dilutive: As of June 30, 2019 2018 Options to purchase common stock 19,771,277 22,932,222 Common stock issuable upon conversion of redeemable convertible preferred stock — 61,279,079 Common stock issuable upon exercise of common stock warrants 500,000 500,000 Common stock issuable upon exercise and redeemable conversion of preferred stock warrants — 398,331 Common stock issuable upon vesting of restricted stock units 1,213,337 — Common stock issuable in connection with employee stock purchase plan 802,389 — Total 22,287,003 85,109,632

Segment and Geographical Info_2

Segment and Geographical Information (Tables)	6 Months Ended
	Jun. 30, 2019
Segment Reporting [Abstract]
Revenue by Type of Service	The following table sets forth total revenue by type of service for the periods presented (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Marketplace $ 66,201 $ 55,454 $ 127,104 $ 107,413 Managed services 8,055 7,227 16,076 14,486 Total revenue $ 74,256 $ 62,681 $ 143,180 $ 121,899
Revenue by Geographic Area Based on Billing Address of Freelancers and Clients	The following table sets forth total revenue by geographic area based on the billing address of its freelancers and clients for the periods presented (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2019 2018 2019 2018 Freelancers United States $ 12,486 $ 9,554 $ 24,374 $ 18,657 India 6,904 6,467 13,534 12,573 Philippines 4,929 4,203 9,506 8,158 Rest of world 22,588 20,159 44,283 39,184 Total freelancers 46,907 40,383 91,697 78,572 Clients United States 21,431 18,187 39,105 33,649 Rest of world 5,918 4,111 12,378 9,678 Total clients 27,349 22,298 51,483 43,327 Total revenue $ 74,256 $ 62,681 $ 143,180 $ 121,899

Organization and Description _2

Organization and Description of Business (Details) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2015platform
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating platforms consolidated | platform		2
Subsidiary, Sale of Stock [Line Items]
Consideration received on stock transaction | $	$ 109.4
IPO
Subsidiary, Sale of Stock [Line Items]
Number of shares issued in stock transaction | shares	7,840,908
Price per share of stock transaction (in dollars per share) | $ / shares	$ 15
Underwriters' Option
Subsidiary, Sale of Stock [Line Items]
Number of shares issued in stock transaction | shares	1,022,727
Price per share of stock transaction (in dollars per share) | $ / shares	$ 1.05

Fair Value Measurements - Finan

Fair Value Measurements - Financial Liabilities Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	$ 116,109	$ 117,138
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	51,169	117,138
Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	2,498
Marketable securities	42,481
Treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	4,991
U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	14,970
Level I
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	71,130	117,138
Level I | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	51,169	117,138
Level I | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Marketable securities	0
Level I | Treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	4,991
Level I | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	14,970
Level II
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	44,979	0
Level II | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0
Level II | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	2,498
Marketable securities	42,481
Level II | Treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0
Level II | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0
Level III
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	0	0
Level III | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	$ 0
Level III | Commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0
Marketable securities	0
Level III | Treasury bills
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	0
Level III | U.S. government securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Marketable securities	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other (income) expense, net	$ (832)	$ 173	$ (1,311)	$ 422
Redeemable Convertible Preferred Stock Warrant Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other (income) expense, net		$ 100		$ 400

Balance Sheet Components - Cash

Balance Sheet Components - Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2018	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Cash	$ 13,425	$ 11,990
Money market funds	51,169	117,138
Commercial paper	2,498	0
Total cash and cash equivalents	$ 67,092	$ 129,128	$ 31,331	$ 21,595

Balance Sheet Components - Mark

Balance Sheet Components - Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Marketable Securities [Line Items]
Total marketable securities	$ 62,442	$ 0
Commercial paper
Marketable Securities [Line Items]
Total marketable securities	42,481
Treasury bills
Marketable Securities [Line Items]
Total marketable securities	4,991
U.S. government securities
Marketable Securities [Line Items]
Total marketable securities	$ 14,970

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment, Net (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 25,294,000		$ 25,294,000		$ 17,804,000
Less: accumulated depreciation	(6,087,000)		(6,087,000)		(6,989,000)
Property and equipment, net	19,207,000		19,207,000		10,815,000
Depreciation expense	600,000	$ 500,000	1,400,000	$ 900,000
Capitalized internal-use software and platform development costs	1,400,000	1,300,000	2,500,000	1,900,000
Amortization of internal-use software and platform development costs		$ 0		$ 0
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total property and equipment	3,750,000		3,750,000		3,189,000
Internal-use software and platform development
Property, Plant and Equipment [Line Items]
Total property and equipment	8,820,000		8,820,000		6,287,000
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	10,433,000		10,433,000		5,783,000
Office furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 2,291,000		$ 2,291,000		$ 2,545,000

Balance Sheet Components - Inta

Balance Sheet Components - Intangible Assets, Net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 31,856		$ 31,856		$ 31,856
Accumulated Amortization	27,186		27,186		25,852
Net Carrying Amount	4,670		4,670		6,004
Amortization expense of intangible assets	700	$ 700	1,300	$ 1,300
Trade names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	2,293		2,293		2,293
Accumulated Amortization	2,293		2,293		2,293
Net Carrying Amount	0		0		0
User relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	18,678		18,678		18,678
Accumulated Amortization	14,008		14,008		12,674
Net Carrying Amount	4,670		$ 4,670		$ 6,004
Remaining useful life			1 year 9 months		2 years 3 months
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	10,356		$ 10,356		$ 10,356
Accumulated Amortization	10,356		10,356		10,356
Net Carrying Amount	0		0		0
Domain names
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	529		529		529
Accumulated Amortization	529		529		529
Net Carrying Amount	$ 0		$ 0		$ 0

Balance Sheet Components - Esti

Balance Sheet Components - Estimated Future Amortization Expense for Acquired Intangible Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Remainder of 2019	$ 1,334
2020	2,668
2021	668
Net Carrying Amount	$ 4,670	$ 6,004

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
Accrued compensation and related benefits	$ 3,712	$ 9,314
Accrued freelancer costs	799	2,465
Accrued indirect taxes	2,192	1,630
Accrued vendor expenses	11,150	6,002
Accrued payment processing fees	776	715
Other	503	822
Total accrued expenses and other current liabilities	$ 19,132	$ 20,948

Commitments and Contingencies -

Commitments and Contingencies - Operating Leases (Details) $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)agreement	Jun. 30, 2018USD ($)	Dec. 31, 2018agreementoffice_space
Lessee, Lease, Description [Line Items]
Number of non-cancellable operating lease agreements | agreement				5
Lease payment, year 2	$ 5,921			$ 5,921
Lease payment, year 3	6,405			6,405
Lease payment, year 4	6,588			6,588
Lease payment, year 5	6,776			6,776
Lease payment, thereafter	13,137			13,137
Accelerated depreciation		$ 300
Rent expense	1,500		$ 900	2,700	$ 1,900
Santa Clara
Lessee, Lease, Description [Line Items]
Total minimum lease payments	14,300			14,300
Santa Clara | Minimum
Lessee, Lease, Description [Line Items]
Total minimum lease payments	1,400			1,400
Lease payment, year 1	1,400			1,400
Lease payment, year 2	1,400			1,400
Lease payment, year 3	1,400			1,400
Lease payment, year 4	1,400			1,400
Lease payment, year 5	1,400			1,400
Lease payment, thereafter	1,400			1,400
Santa Clara | Maximum
Lessee, Lease, Description [Line Items]
Total minimum lease payments	1,800			1,800
Lease payment, year 1	1,800			1,800
Lease payment, year 2	1,800			1,800
Lease payment, year 3	1,800			1,800
Lease payment, year 4	1,800			1,800
Lease payment, year 5	1,800			1,800
Lease payment, thereafter	1,800			1,800
San Francisco
Lessee, Lease, Description [Line Items]
Total minimum lease payments	15,700			15,700
San Francisco | Minimum
Lessee, Lease, Description [Line Items]
Total minimum lease payments	1,000			1,000
Lease payment, year 1	1,000			1,000
Lease payment, year 2	1,000			1,000
Lease payment, year 3	1,000			1,000
Lease payment, year 4	1,000			1,000
Lease payment, year 5	1,000			1,000
San Francisco | Maximum
Lessee, Lease, Description [Line Items]
Total minimum lease payments	2,200			2,200
Lease payment, year 1	2,200			2,200
Lease payment, year 2	2,200			2,200
Lease payment, year 3	2,200			2,200
Lease payment, year 4	2,200			2,200
Lease payment, year 5	2,200			2,200
Chicago
Lessee, Lease, Description [Line Items]
Total minimum lease payments	10,300			10,300
Number of sublease agreements | agreement						2
Number of leased spaces | office_space						2
Chicago | Minimum
Lessee, Lease, Description [Line Items]
Total minimum lease payments	500			500
Lease payment, year 1	500			500
Lease payment, year 2	500			500
Lease payment, year 3	500			500
Lease payment, year 4	500			500
Lease payment, year 5	500			500
Lease payment, thereafter	500			500
Chicago | Maximum
Lessee, Lease, Description [Line Items]
Total minimum lease payments	2,000			2,000
Lease payment, year 1	2,000			2,000
Lease payment, year 2	2,000			2,000
Lease payment, year 3	2,000			2,000
Lease payment, year 4	2,000			2,000
Lease payment, year 5	2,000			2,000
Lease payment, thereafter	$ 2,000			$ 2,000

Commitments and Contingencies_2

Commitments and Contingencies - Future Aggregate Minimum Lease Payments Under Non-Cancelable Operating Leases (Details) $ in Thousands	Jun. 30, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
Remainder of 2019	$ 1,722
2020	5,921
2021	6,405
2022	6,588
2023	6,776
Thereafter	13,137
Less: sublease income	(656)
Total	$ 39,893

Commitments and Contingencies_3

Commitments and Contingencies - Letters of Credit (Details) $ in Millions	Jun. 30, 2019USD ($)letter	Dec. 31, 2018USD ($)letter
Commitments and Contingencies Disclosure [Abstract]
Letters of credit held | letter	4	3
Letters of credit outstanding | $	$ 1.1	$ 0.8

Debt - Summary of Carrying Valu

Debt - Summary of Carrying Value of Debt (Details)	1 Months Ended		3 Months Ended	6 Months Ended	8 Months Ended
	Oct. 31, 2018	Sep. 30, 2018USD ($)installment	Dec. 31, 2018USD ($)	Jun. 30, 2019USD ($)installment	Aug. 31, 2018
Debt Instrument [Line Items]
Total debt			$ 24,000,000	$ 47,107,000
Less: unamortized debt discount issuance costs			(90,000)	(64,000)
Balance			23,910,000	47,043,000
Debt, current			(5,671,000)	(32,574,000)
Debt, noncurrent			$ 18,239,000	$ 14,469,000
Weighted-average interest rate			6.89%	5.96%
First Term Loan
Debt Instrument [Line Items]
Total debt			$ 15,000,000	$ 13,750,000
Interest only payments term				18 months
Number of equal monthly installments of principal and interest | installment				36
First Term Loan | Prime Rate
Debt Instrument [Line Items]
Debt, variable rate				0.25%
Second Term Loan
Debt Instrument [Line Items]
Total debt			$ 9,000,000	$ 8,357,000
Interest only payments term				11 months
Number of equal monthly installments of principal and interest | installment		42		47
EBITDA, trailing period		6 months
EBITDA		$ 1,000,000
Second Term Loan | Prime Rate
Debt Instrument [Line Items]
Debt, variable rate	0.25%	5.25%	0.25%		5.25%
Line of Credit
Debt Instrument [Line Items]
Total debt			$ 0	$ 25,000,000

Debt - Additional Information (

Debt - Additional Information (Details)	1 Months Ended				3 Months Ended		6 Months Ended		8 Months Ended	12 Months Ended
	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Oct. 31, 2018	Sep. 30, 2018USD ($)	Jun. 30, 2019USD ($)	Dec. 31, 2018	Jun. 30, 2019USD ($)	Jun. 30, 2018USD ($)	Aug. 31, 2018	Dec. 31, 2018
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 49,000,000				$ 49,000,000		$ 49,000,000
Net proceeds				$ 50,000,000
Adjusted quick ratio		1.75								1.30
Adjusted quick ratio to maintain to reduce frequency of providing financial information		2.50
Proceeds from borrowings on debt	25,000,000	$ 25,000,000					50,000,000	$ 0
Repayment of debt							26,893,000	$ 0
Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	25,000,000				25,000,000		25,000,000
First Term Loan
Debt Instrument [Line Items]
Debt instrument, face amount	15,000,000				15,000,000		$ 15,000,000
Repayment of debt					1,300,000
First Term Loan | Prime Rate
Debt Instrument [Line Items]
Debt, variable rate							0.25%
Second Term Loan
Debt Instrument [Line Items]
Debt instrument, face amount	$ 9,000,000				9,000,000		$ 9,000,000
Repayment of debt					$ 600,000
Second Term Loan | Prime Rate
Debt Instrument [Line Items]
Debt, variable rate			0.25%	5.25%		0.25%			5.25%

Redeemable Convertible Prefer_2

Redeemable Convertible Preferred Stock (Details)	Jun. 30, 2019shares	Mar. 31, 2019shares	Dec. 31, 2018shares	Jun. 30, 2018shares	Mar. 31, 2018shares	Dec. 31, 2017shares
Temporary Equity Disclosure [Abstract]
Redeemable convertible preferred stock, shares outstanding	0	0	0	61,279,079	61,279,079	61,279,079
Conversion ratio						1
Redeemable convertible preferred stock, shares issued	0		0

Preferred and Common Stock Wa_2

Preferred and Common Stock Warrants - Redeemable Convertible Preferred Stock Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Apr. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Class of Warrant or Right [Line Items]
Other (income) expense, net		$ (832)	$ 173	$ (1,311)	$ 422
Cost of warrant exercised	$ 1,200
Number of shares surrendered (in shares)	64,646
Number of shares issued resulting from exercise (in shares)	333,685
Redeemable Convertible Preferred Stock Warrant Liability
Class of Warrant or Right [Line Items]
Other (income) expense, net			$ 100		$ 400
Redeemable Convertible Preferred Stock Warrants | Series A-1 Redeemable Convertible Preferred Stock
Class of Warrant or Right [Line Items]
Number of shares issued upon exercisable of warrants		124,506		124,506
Exercise price of warrants (in dollars per share)		$ 3.13		$ 3.13
Redeemable Convertible Preferred Stock Warrants | Series A-2 Redeemable Convertible Preferred Stock
Class of Warrant or Right [Line Items]
Number of shares issued upon exercisable of warrants		273,825		273,825

Preferred and Common Stock Wa_3

Preferred and Common Stock Warrants - Common Stock Warrant (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2018	May 31, 2018
Class of Warrant or Right [Line Items]
Percentage of shares on which warrant is exercisable	10.00%	10.00%
Change in fair value of Tides Foundation common stock warrant	$ 200	$ 377	$ 0
Tides Foundation | Common Stock Warrant
Class of Warrant or Right [Line Items]
Number of shares issued upon exercisable of warrants				500,000
Exercise price of warrants (in dollars per share)				$ 0.01

Common Stock - Additional Infor

Common Stock - Additional Information (Details) - shares	6 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Equity [Abstract]
Common Stock, voting rights	one vote per share
Common stock, shares authorized	490,000,000	490,000,000

Common Stock - Summary of Commo

Common Stock - Summary of Common Stock Shares Reserved for Future Issuance (Details) - shares	Jun. 30, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Common stock shares reserved for future issuance	39,076,438	37,219,376
2018 ESPP
Class of Stock [Line Items]
Common stock shares reserved for future issuance	2,271,326	1,700,000
2018 Equity Incentive Plan
Class of Stock [Line Items]
Common stock shares reserved for future issuance	15,320,498	10,558,306
Options issued and outstanding
Class of Stock [Line Items]
Common stock shares reserved for future issuance	19,771,277	23,774,279
RSUs issued and outstanding
Class of Stock [Line Items]
Common stock shares reserved for future issuance	1,213,337	288,460
Warrant to purchase common stock
Class of Stock [Line Items]
Common stock shares reserved for future issuance	500,000	898,331

Stock-Based Compensation - Acti

Stock-Based Compensation - Activity under Stock Option Plans (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)$ / sharesshares
Number of Shares Underlying Outstanding Options
Balances at beginning of period (in shares) | shares	23,774,279
Exercised (in shares) | shares	(3,584,854)
Forfeited and canceled (in shares) | shares	(418,148)
Balances at end of period (in shares) | shares	19,771,277	23,774,279
Weighted-Average Exercise Price
Balances at beginning of period (in dollars per share) | $ / shares	$ 3.71
Exercised (in dollars per share) | $ / shares	2.89
Forfeited and canceled (in dollars per share) | $ / shares	4.78
Balances at beginning of period (in dollars per share) | $ / shares	$ 3.84	$ 3.71
Weighted-Average Remaining Contractual Term (Years)	6 years 9 months 22 days	7 years 1 month 6 days
Aggregate Intrinsic Value | $	$ 241,977	$ 342,262

Stock-Based Compensation - Ac_2

Stock-Based Compensation - Activity under RSU Plans (Details) - RSUs	6 Months Ended
	Jun. 30, 2019$ / sharesshares
Number of RSUs Outstanding
Unvested Balance at beginning of period (in shares) | shares	288,460
Granted (in shares) | shares	1,025,786
Vested (in shares) | shares	(55,362)
Forfeited and Canceled (in shares) | shares	(45,547)
Unvested Balance at end of period (in shares) | shares	1,213,337
Weighted-Average Grant Date Fair Value
Unvested Balance at beginning of period (in dollars per share) | $ / shares	$ 15
Granted (in dollars per share) | $ / shares	19.16
Vested (in dollars per share) | $ / shares	15.30
Forfeited and Canceled (in dollars per share) | $ / shares	18.22
Unvested Balance at end of period (in dollars per share) | $ / shares	$ 18.38

Stock-Based Compensation - Equi

Stock-Based Compensation - Equity Incentive Plans, Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Jan. 31, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Jul. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based expense		$ 2,631	$ 1,793	$ 6,926	$ 3,681
Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option to purchase shares of common stock, granted						1,860,000
Share-based expense		$ 900		$ 1,400
2018 EIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in number of shares available for issuance	5,322,716

Stock-Based Compensation - Empl

Stock-Based Compensation - Employee Stock Purchase Plan (Details) - 2018 ESPP - shares	1 Months Ended	3 Months Ended
	Jan. 31, 2019	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in number of shares available for issuance	851,634
Issuance of common stock in connection with employee stock purchase plan (in shares)		280,308

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 2,631	$ 1,793	$ 6,926	$ 3,681
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	73	53	217	105
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	1,686	538	3,066	1,088
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	583	331	1,225	671
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 289	$ 871	$ 2,418	$ 1,817

Net Loss per Share - Summary of

Net Loss per Share - Summary of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator:
Net loss	$ (2,027)	$ (412)	$ (6,755)	$ (7,196)
Denominator:
Weighted-average shares used to compute net loss per share, basic and diluted (in shares)	108,683,099	35,104,769	107,665,492	34,651,331
Net loss per share, basic and diluted (in dollars per share)	$ (0.02)	$ (0.01)	$ (0.06)	$ (0.21)

Net Loss per Share - Schedule o

Net Loss per Share - Schedule of Potentially Dilutive Securities Excluded from Computation of Diluted Net Loss Per Share Attributable to Common Stockholders (Details) - shares	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from computation of diluted net loss per share attributable to common stockholders	22,287,003	85,109,632
Options to Purchase Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from computation of diluted net loss per share attributable to common stockholders	19,771,277	22,932,222
Common Stock Issuable upon Conversion of Redeemable Convertible Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from computation of diluted net loss per share attributable to common stockholders	0	61,279,079
Common Stock Issuable upon Exercise of Common Stock Warrant
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from computation of diluted net loss per share attributable to common stockholders	500,000	500,000
Common Stock Issuable upon Exercise and Redeemable Conversion of Preferred Stock Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from computation of diluted net loss per share attributable to common stockholders	0	398,331
Restricted Stock Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from computation of diluted net loss per share attributable to common stockholders	1,213,337	0
Employee Stock Purchase Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares excluded from computation of diluted net loss per share attributable to common stockholders	802,389	0

Segment and Geographical Info_3

Segment and Geographical Information - Additional Information (Details)	6 Months Ended
	Jun. 30, 2019segment
Segment Reporting [Abstract]
Number of operating segments	1
Number of reportable segments	1

Segment and Geographical Info_4

Segment and Geographical Information - Revenue by Type of Service (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 74,256	$ 62,681	$ 143,180	$ 121,899
Marketplace
Disaggregation of Revenue [Line Items]
Revenue	66,201	55,454	127,104	107,413
Managed services
Disaggregation of Revenue [Line Items]
Revenue	$ 8,055	$ 7,227	$ 16,076	$ 14,486

Segment and Geographical Info_5

Segment and Geographical Information - Revenue by Geographic Area Based on Billing Address of Freelancers and Clients (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 74,256	$ 62,681	$ 143,180	$ 121,899
Freelancers
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	46,907	40,383	91,697	78,572
Freelancers | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	12,486	9,554	24,374	18,657
Freelancers | India
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	6,904	6,467	13,534	12,573
Freelancers | Philippines
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	4,929	4,203	9,506	8,158
Freelancers | Rest of world
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	22,588	20,159	44,283	39,184
Clients
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	27,349	22,298	51,483	43,327
Clients | United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	21,431	18,187	39,105	33,649
Clients | Rest of world
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 5,918	$ 4,111	$ 12,378	$ 9,678

401(k) Plan (Details)

401(k) Plan (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Retirement Benefits [Abstract]
Company matching cash contributions			50.00%
Maximum annual contributions per employee			$ 5,000
Expense for matching contributions	$ 500,000	$ 300,000	$ 1,400,000	$ 1,100,000

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Thousands	1 Months Ended	6 Months Ended
	Jul. 31, 2019	Jun. 30, 2019	Jun. 30, 2018
Subsequent Event [Line Items]
Repayment of debt		$ 26,893	$ 0
Subsequent Event | Line of Credit
Subsequent Event [Line Items]
Repayment of debt	$ 25,000