Color Contrast Checker

Check WCAG color contrast ratio between foreground and background colors and verify AA/AAA compliance. Free, private, and 100% client-side.

Input

Output

Local only

Recent history

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How to use

Enter two colors (foreground and background) separated by a newline or space.
Read the contrast ratio and AA/AAA compliance results.
Adjust colors to meet your accessibility target.

Frequently asked questions

What is the WCAG contrast ratio?: The ratio is (L1 + 0.05) / (L2 + 0.05) where L1 and L2 are the relative luminances of the lighter and darker colors. Black on white yields 21:1.
What are the AA and AAA thresholds?: AA requires 4.5:1 for normal text and 3:1 for large text. AAA requires 7:1 for normal text and 4.5:1 for large text.

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