Normal text sample — The quick brown fox.
Large text sample (18pt+)
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Contrast ratio
| Standard | Level | Min ratio | Result |
|---|---|---|---|
| Normal text | WCAG AA | 4.5:1 | — |
| Large text (≥18pt / ≥14pt bold) | WCAG AA | 3:1 | — |
| Normal text | WCAG AAA | 7:1 | — |
| Large text (≥18pt / ≥14pt bold) | WCAG AAA | 4.5:1 | — |
How to use the Color Contrast Checker
- Use the color pickers or enter HEX codes for foreground (text) and background colors.
- The contrast ratio and WCAG compliance results update instantly.
- Use Swap to reverse foreground and background.
WCAG contrast requirements
- AA — Normal text: minimum 4.5:1. Required for WCAG 2.1 Level AA compliance.
- AA — Large text: minimum 3:1. Large text is 18pt (24px) regular or 14pt (18.67px) bold.
- AAA — Normal text: minimum 7:1. Enhanced accessibility standard.
- AAA — Large text: minimum 4.5:1.
How contrast ratio is calculated
Relative luminance (L) is calculated from the sRGB color channels after gamma linearization: L = 0.2126R + 0.7152G + 0.0722B. The ratio is (L1 + 0.05) / (L2 + 0.05) where L1 is the lighter color.