| Document And Entity Information | Sep. 27, 2021 |
| Document Information [Line Items] | |
| Entity, Registrant Name | BYRNA TECHNOLOGIES INC. |
| Document, Type | 8-K |
| Document, Period End Date | Sep. 27, 2021 |
| Entity, Incorporation, State or Country Code | DE |
| Entity, File Number | 333-132456 |
| Entity, Tax Identification Number | 71-1050654 |
| Entity, Address, Address Line One | 100 Burtt Road |
| Entity, Address, Address Line Two | Suite 115 |
| Entity, Address, City or Town | Andover |
| Entity, Address, State or Province | MA |
| Entity, Address, Postal Zip Code | 01810 |
| City Area Code | 978 |
| Local Phone Number | 868-5011 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | BYRN |
| Security Exchange Name | NASDAQ |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0001354866 |
