Cover
Cover - shares | 9 Months Ended | |
Sep. 30, 2021 | Aug. 19, 2021 | |
Cover [Abstract] | ||
Document Type | 10-Q/A | |
Amendment Flag | false | |
Document Quarterly Report | true | |
Document Transition Report | false | |
Document Period End Date | Sep. 30, 2021 | |
Document Fiscal Period Focus | Q3 | |
Document Fiscal Year Focus | 2021 | |
Current Fiscal Year End Date | --12-31 | |
Entity File Number | 001-35521 | |
Entity Registrant Name | CLEARSIGN TECHNOLOGIES CORPORATION | |
Entity Central Index Key | 0001434524 | |
Entity Tax Identification Number | 26-2056298 | |
Entity Incorporation, State or Country Code | WA | |
Entity Address, Address Line One | 12870 Interurban Avenue South | |
Entity Address, City or Town | Seattle | |
Entity Address, State or Province | WA | |
Entity Address, Postal Zip Code | 98168 | |
City Area Code | 206 | |
Local Phone Number | 673-4848 | |
Title of 12(b) Security | Common Stock | |
Trading Symbol | CLIR | |
Security Exchange Name | NASDAQ | |
Entity Current Reporting Status | Yes | |
Entity Interactive Data Current | Yes | |
Entity Filer Category | Non-accelerated Filer | |
Entity Small Business | true | |
Entity Emerging Growth Company | false | |
Entity Shell Company | false | |
Entity Common Stock, Shares Outstanding | 31,482,454 |