| Cover | Sep. 27, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Sep. 27, 2021 |
| Entity File Number | 001-40336 |
| Entity Registrant Name | Karat Packaging Inc. |
| Entity Central Index Key | 0001758021 |
| Entity Tax Identification Number | 83-2237832 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 6185 Kimball Avenue |
| Entity Address, City or Town | Chino |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 91708 |
| City Area Code | 626 |
| Local Phone Number | 965-8882 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $0.001 par value per share |
| Trading Symbol | KRT |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
