Color Contrast Checker
Enter a foreground and background color to get the exact contrast ratio and WCAG AA/AAA pass or fail.
Colors
Check contrast against WCAG standards
The Web Content Accessibility Guidelines (WCAG) set minimum contrast ratios between text and its background so content stays readable, including for people with low vision. Enter any two colors to get the exact ratio and see whether it passes AA (the widely required minimum) or the stricter AAA level, for both normal and large text sizes.
The thresholds
AA requires a 4.5:1 ratio for normal text and 3:1 for large text (18pt+, or 14pt+ bold). AAA is stricter: 7:1 for normal text and 4.5:1 for large text. Large text needs less contrast because bigger shapes are easier to distinguish even at lower contrast.
Also useful: Unit Converter and Password Generator.
Frequently asked questions
WCAG defines large text as 18pt (24px) and up, or 14pt (about 18.5px) and up if bold. Anything smaller is judged against the stricter normal-text thresholds.
AA is the standard most legal accessibility requirements (like the ADA and Section 508) reference and is considered the practical baseline. AAA is a stricter, optional target worth aiming for on critical text, especially body copy.
No — contrast ratio measures relative luminance difference, which matters for all vision types, but it doesn't fully capture how specific hue pairs (like red/green) are perceived by colorblind users. Pair a good contrast ratio with not relying on color alone to convey meaning.