Check whether two colours have enough contrast for readable text. Pick a text colour and a background colour, then see the WCAG contrast ratio with pass or fail ratings for normal and large text. Free, instant and private, with no sign-up needed.
How to Use
- Pick a text colour and a background colour with the colour pickers.
- Read the contrast ratio and the PASS/FAIL ratings for normal and large text.
- Adjust the colours until both ratings pass for accessible, readable text.
Key Features
- WCAG 2.1 ratios – the same contrast formula the accessibility guidelines use.
- Instant ratings – PASS/FAIL for normal text (AA) and large text (AA).
- Live preview – see your colour pair on real text straight away.
- 100% private – everything runs in your browser; nothing is sent anywhere.
FAQs
Is this color contrast checker free?
Yes. It is completely free with no sign-up and no limits.
What contrast ratio should I aim for?
For normal body text, WCAG AA requires a ratio of at least 4.5:1. For large text (roughly 18pt or 14pt bold and above), 3:1 is the minimum.
How is the ratio calculated?
Each colour’s relative luminance is worked out from its red, green and blue channels, then the ratio is (lighter + 0.05) divided by (darker + 0.05). Ratios range from 1:1 (no contrast) to 21:1 (black on white).
Is my data stored anywhere?
No. The check runs entirely in your browser and nothing is transmitted or saved.
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