| Document and Entity Information | Aug. 11, 2023 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001821323 |
| Current Fiscal Year End Date | --12-31 |
| Document Type | 8-K |
| Document Period End Date | Aug. 11, 2023 |
| Entity Registrant Name | SIGILON THERAPEUTICS, INC. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-39746 |
| Entity Tax Identification Number | 47-4005543 |
| Entity Address, Address Line One | 100 Binney Street |
| Entity Address, Address Line Two | Suite 600 |
| Entity Address, City or Town | Cambridge |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 02142 |
| City Area Code | (617) |
| Local Phone Number | 336-7540 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common stock, $0.001 par value per share |
| Trading Symbol | SGTX |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
