| Cover Page Document | Jan. 27, 2025 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Jan. 27, 2025 |
| Entity Registrant Name | CARTESIAN THERAPEUTICS, INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-37798 |
| Entity Tax Identification Number | 26-1622110 |
| Entity Address, Address Line One | 7495 New Horizon Way, |
| Entity Address, City or Town | Frederick, |
| Entity Address, State or Province | MD |
| Entity Address, Postal Zip Code | 21703 |
| City Area Code | 301 |
| Local Phone Number | 348-8698 |
| 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) |
| Trading Symbol | RNAC |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001453687 |
| Amendment Flag | false |
