| Document and Entity Information | Nov. 24, 2020 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001540755 |
| Document Type | 8-K |
| Document Period End Date | Nov. 24, 2020 |
| Entity Registrant Name | ANAPLAN, INC. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-38698 |
| Entity Tax Identification Number | 27-0897861 |
| Entity Address, Address Line One | 50 Hawthorne Street |
| Entity Address, City or Town | San Francisco |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94105 |
| City Area Code | (415) |
| Local Phone Number | 742-8199 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, $0.0001 par value per share |
| Trading Symbol | PLAN |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
