About this tool: Color Contrast Checker
Check two colors against WCAG AA and AAA text contrast thresholds.
Contrast is calculated from relative luminance, independently of hue. WCAG AA requires at least 4.5:1 for normal text and 3:1 for large text; AAA uses 7:1 and 4.5:1. Decisions use the unrounded ratio, so a rounded display near a threshold does not change the outcome.
How the calculation works
Worked example
| Text color | #4f46e5 |
| Background color | #ffffff |
≈ 6.288:1; AA ✓; AAA (normal) ✗
Questions and answers
What does this tool do?
Check two colors against WCAG AA and AAA text contrast thresholds. Contrast is calculated from relative luminance, independently of hue. WCAG AA requires at least 4.5:1 for normal text and 3:1 for large text; AAA uses 7:1 and 4.5:1. Decisions use the unrounded ratio, so a rounded display near a threshold does not change the outcome.
What affects precision and input format?
WCAG decisions use the unrounded contrast ratio. Only opaque RGB colors are supported.
Where are the calculations performed?
The calculation runs in your browser. You can use the tool without installing software.
Asted Cloud
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