| Document And Entity Information | Nov. 11, 2022 |
| Document Information [Line Items] | |
| Entity, Registrant Name | LiqTech International, Inc. |
| Document, Type | 8-K |
| Document, Period End Date | Nov. 11, 2022 |
| Entity, Incorporation, State or Country Code | NV |
| Entity, File Number | 001-36210 |
| Entity, Tax Identification Number | 20-1431677 |
| Entity, Address, Address Line One | Industriparken 22C |
| Entity, Address, Postal Zip Code | 2750 |
| Entity, Address, City or Town | Ballerup |
| Entity, Address, Country | DK |
| City Area Code | 45 |
| Local Phone Number | 3131 5941 |
| 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 | LIQT |
| Security Exchange Name | NASDAQ |
| Entity, Emerging Growth Company | false |
| Amendment Flag | false |
| Entity, Central Index Key | 0001307579 |
