Reference
Readable, or not. There is a number for it.
Enter a text color and a background color. This returns the contrast ratio for that pair and whether it clears each WCAG threshold. Nothing is sent anywhere, and the page address carries the pair so you can share it.
The pair
Set two colors.
What this does
It measures one thing, exactly.
Contrast is a ratio between the relative luminance of two colors. The calculation is fixed and published, so it does not move with taste, screen or brand. This applies that formula to the pair you enter and reports the four thresholds the standard defines, which lets you settle the question before the color reaches a page rather than after a visitor cannot read it.
The limits
What this cannot tell you.
This checks one color pair. It is not a complete accessibility audit.
- A page has dozens of pairs. Text on cards, text on images, borders, focus rings, disabled states and every hover. This reads the one you typed.
- It says nothing about keyboard access, focus order, heading structure, form labels or alternative text, which is where most real barriers live.
- The large-text thresholds assume roughly 24px, or 19px bold. This tool cannot see the size and weight your page actually renders.
- An automated check never replaces evaluation by people who use assistive technology.
- Passing AA is a floor, not a finish. It is the point at which the text stops being the problem.
The 2026 WebAIM Million report found detectable WCAG failures on 95.9% of the top one million homepages.
Context: The WebAIM Million, 2026 report
Read next
The same measurement applied to a million real homepages, and the short list of fixes that clears most of what it finds.
Website Accessibility in 2026: The Data and the FixesWant the rest of the page checked?
The audit runs contrast across your actual pages alongside keyboard access, headings and labels, then names what is worth fixing first. You get the findings whether or not you hire me.