| Document And Entity Information | Feb. 02, 2022 |
| Document Information [Line Items] | |
| Entity, Registrant Name | BIO-key International, Inc. |
| Document, Type | 8-K |
| Document, Period End Date | Feb. 2, 2022 |
| Entity, Incorporation, State or Country Code | DE |
| Entity, File Number | 1-13463 |
| Entity, Tax Identification Number | 41-1741861 |
| Entity, Address, Address Line One | 3349 Highway 138 |
| Entity, Address, Address Line Two | Building A |
| Entity, Address, Address Line Three | Suite E |
| Entity, Address, City or Town | Wall |
| Entity, Address, State or Province | NJ |
| Entity, Address, Postal Zip Code | 07719 |
| City Area Code | 732 |
| Local Phone Number | 359-1100 |
| Title of 12(b) Security | Common Stock |
| Trading Symbol | BKYI |
| Security Exchange Name | NASDAQ |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0001019034 |
