Colour contrast checker.
Enter two colours and get the exact ratio, plus whether it passes WCAG 2.2 at AA and AAA. Runs in your browser — nothing is uploaded, nothing is stored, no signup.
Large text, 24px
Body text at the size most of your site actually uses.
4.63:1
- AA normal text —
- AA large text —
- AAA normal text —
- AAA large text —
- AA UI & graphics —
Large text means 18.66 px bold or 24 px regular and above. UI & graphics covers interface components and meaningful graphics, which need 3:1 under success criterion 1.4.11.
Contrast is one criterion out of dozens, and it is the one a tool measures best. Passing it does not mean a page is usable — it means one specific thing is not broken.
Why this one matters more than most
Insufficient contrast is consistently the single most common accessibility failure on the web, and it is also among the cheapest to fix — usually a hex value in a design token, not a rebuild.
It is worth checking your actual states too, not just body text: placeholder text, disabled buttons, focus indicators, error messages, and text sitting over an image. Those are where contrast quietly fails after a design system has been signed off.