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Check colours against WCAG AA and AAA contrast.
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Setting up your workspace on this device.
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Colour Contrast Checker calculates the contrast ratio between a text colour and its background and checks it against WCAG 2.2 — AA and AAA for normal text, large text and interface components. A live preview shows how the colours look, and if a pair fails, it suggests the nearest shade of your text colour that passes AA.
Open Colour Contrast Checker
Launch Colour Contrast Checker directly in your browser — there is nothing to download, install, or configure first.
Paste your input
Paste or type your input into Colour Contrast Checker to begin.
Get the formatted output
Colour Contrast Checker processes your input instantly in the browser and shows the result, ready to copy.
WCAG AA needs 4.5:1 for normal text and 3:1 for large text (18pt, or 14pt bold) and interface parts. AAA needs 7:1 and 4.5:1.
It uses the WCAG relative-luminance formula: (L1 + 0.05) ÷ (L2 + 0.05), where L1 is the lighter colour. Black on white is 21:1.
Yes. Colour Contrast Checker is completely free, with no account, no paywall, and no usage limits.
No. Colour Contrast Checker works instantly in any modern web browser — there is no software to install, no extension, and no sign-up.