| Document And Entity Information | Mar. 19, 2024 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Mar. 19, 2024 |
| Entity Registrant Name | Adicet Bio, Inc. |
| Entity Central Index Key | 0001720580 |
| Entity Emerging Growth Company | false |
| Entity File Number | 001-38359 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 81-3305277 |
| Entity Address, Address Line One | 131 Dartmouth Street, Floor 3 |
| Entity Address, City or Town | Boston |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 02116 |
| City Area Code | (650) |
| Local Phone Number | 503-9095 |
| Entity Information, Former Legal or Registered Name | Not applicable |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.0001 per share |
| Trading Symbol | ACET |
| Security Exchange Name | NONE |
