How to use this tool
Pick opaque text and background colours. The result compares their WCAG relative luminance contrast ratio.
A quick example
Black on white has a contrast ratio of 21:1.
Supported formats & limitations
Normal text needs 4.5:1 for AA and 7:1 for AAA. Large text needs 3:1 for AA and 4.5:1 for AAA (18 pt, or 14 pt bold). Contrast alone does not establish accessibility compliance.
Does this tool upload my input?
No. Tool processing happens in your browser. Your input and result are not automatically saved. The host may still receive ordinary page access logs.Read about privacy.