WCAG Colour Contrast Checker
Improve readability with measured colour contrast rather than guesswork.
Try the tool
Large sample text (23px bold)
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How this tool works
Relative luminance is calculated from sRGB values, with the WCAG contrast formula (L1 + 0.05) ÷ (L2 + 0.05). Normal text generally needs 4.5:1 for AA, large text 3:1; actual accessibility also depends on font weight, size and other aspects.
Practical tip
Contrast does not guarantee legibility. Try a larger type size, generous line spacing, and avoid relying on colour as the sole indicator.
This free tool is informational, with no warranty or professional advice. Check important outputs independently.
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