Compare software

Contrast Ratio vs Ratio: catalog facts
Contrast Ratio	Ratio
Free Free to use in the browser.	Free Free and open source under GPL-3.0-or-later.
Web	macOS, Linux
Updates the ratio live as you type Handles semi-transparent colors with an error margin	Checks text and non-text contrast criteria Supports a focus appearance criterion
Checks one color pair at a time The hosting page includes marketing content from Siege Media	Focused on WCAG criteria 1.4.3, 1.4.11, and 2.4.13
Web application	Downloadable app
Closed source	Open source
License not stated	License: GPL-3.0-or-later
No account needed	No account needed
Not stated if it works offline	Works offline
Official website Full listing and sources Checked September 23, 2026	Official website Full listing and sources Checked October 8, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.