Contrast checks whether your text colour and background pass the WCAG accessibility standards — AA and AAA, for normal and large text — and shows the exact ratio. Type hex values or use the colour pickers; the live preview shows real text. Nothing is uploaded.

Text colour

Background colour

Large text sample

Normal body text sample — the quick brown fox jumps over the lazy dog.

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contrast ratio

The ratio is computed from relative luminance per the WCAG 2.1 formula and ranges from 1:1 (identical) to 21:1 (black on white). "Large text" means 18pt (24px) regular or 14pt (18.66px) bold and above. AA needs 4.5:1 for normal and 3:1 for large; AAA needs 7:1 and 4.5:1. Ratios cover text legibility only, not overall design. Everything runs on your device.