Free qa tool
Color contrast checker
Accessibility starts with readable text. Check the contrast ratio and the WCAG pass level.
Last updated October 31, 2026
How it runs
This tool runs entirely in your browser. Your input is not uploaded or stored.
QA · runs in your browser
free · no accountThe quick brown fox jumps over the lazy dog.
Smaller body copy at 14px.
Ratio
19.90:1
Normal text
AA pass · AAA pass
Large text
AA pass · AAA pass
FAQs
Which formula is used?+
The WCAG relative luminance formula for sRGB colors.
Does a pass guarantee accessibility?+
No. Contrast is one requirement among many.
Related resources
Responsive Checker
Preview a public URL inside phone, tablet and desktop viewports. Sites that block iframes are linked directly.
Website QA Checklist
An interactive pre-launch checklist covering content, forms, auth, mobile, SEO, accessibility, performance and analytics.
SEO Preview Tool
Preview how a title, description and URL may appear in Google, X and Facebook before publishing.
QA testing for developers
Developers and small engineering teams without dedicated QA.
All free tools
Find the bugs your tests never looked for.
Add your app, run an exploratory scan, and get a release verdict backed by evidence.