| Cover | Dec. 11, 2023 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Dec. 11, 2023 |
| Entity File Number | 001-41109 |
| Entity Registrant Name | Intensity Therapeutics, Inc. |
| Entity Central Index Key | 0001567264 |
| Entity Tax Identification Number | 46-1488089 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 1 Enterprise Drive |
| Entity Address, Address Line Two | Suite 430 |
| Entity Address, City or Town | Shelton |
| Entity Address, State or Province | CT |
| Entity Address, Postal Zip Code | 06484-4779 |
| City Area Code | 203 |
| Local Phone Number | 221-7381 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.0001 par value per share |
| Trading Symbol | INTS |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | true |
