Contrast Checker
Check WCAG contrast ratio between two colors.
Calculated locally in your browser.
Overview
Calculates the WCAG contrast ratio between a text color and background color, and checks it against the AA and AAA accessibility thresholds for normal and large text.
How to use it
- 1Choose a text color and background color.
- 2View the contrast ratio and which WCAG levels it passes.
Formula
Contrast ratio
(L1 + 0.05) / (L2 + 0.05)
L1 and L2 are the relative luminance of the lighter and darker colors.
Tips
- AA is the baseline most sites should meet: 4.5:1 for normal text, 3:1 for large text (18pt+, or 14pt+ bold).