| Cover | Aug. 29, 2023 |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Aug. 29, 2023 |
| Current Fiscal Year End Date | --12-31 |
| Entity File Number | 001-40760 |
| Entity Registrant Name | SEQLL INC. |
| Entity Central Index Key | 0001605888 |
| Entity Tax Identification Number | 46-5319744 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 3 Federal Street |
| Entity Address, City or Town | Billerica |
| Entity Address, State or Province | MA |
| Entity Address, Postal Zip Code | 01821 |
| City Area Code | 781 |
| Local Phone Number | 460-6016 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
| Common Stock, par value $.00001 per share | |
| Title of 12(b) Security | Common Stock, par value $.00001 per share |
| Trading Symbol | SQL |
| Security Exchange Name | NASDAQ |
| Warrants to purchase Common Stock | |
| Title of 12(b) Security | Warrants to purchase Common Stock |
| Trading Symbol | SQLLW |
| Security Exchange Name | NASDAQ |
