| Document and Entity Information | Mar. 16, 2022 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Mar. 16, 2022 |
| Entity Registrant Name | Prelude Therapeutics Inc |
| Entity Central Index Key | 0001678660 |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Entity File Number | 001-39527 |
| Entity Incorporation State Country Code | DE |
| Entity Tax Identification Number | 81-1384762 |
| Entity Address, Address Line One | 200 Powder Mill Road |
| Entity Address, City or Town | Wilmington |
| Entity Address, State or Province | DE |
| Entity Address, Postal Zip Code | 19803 |
| City Area Code | (302) |
| Local Phone Number | 467-1280 |
| 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 | PRLD |
| Security Exchange Name | NASDAQ |
