Free Color Contrast Checker — WCAG AA & AAA Accessibility
Color contrast ratio measures the luminance difference between a foreground (text) color and a background color. WCAG 2.1 requires a minimum 4.5:1 for normal text (AA) and 7:1 for AAA. This tool calculates the exact ratio and shows pass/fail status for both standards instantly as you type.
How to use Color Contrast Checker (WCAG)
Enter foreground color
Type your text color as a hex code, RGB, or HSL value.
Enter background color
Type your background color. The contrast ratio updates in real time.
Check WCAG results
See the ratio and pass/fail for WCAG AA (4.5:1) and AAA (7:1) for normal and large text.
Frequently asked questions
WCAG (Web Content Accessibility Guidelines) defines minimum contrast ratios between foreground text and background color to ensure readability for users with low vision or color blindness. WCAG 2.1 Level AA requires 4.5:1 for normal-sized text (below 18pt or 14pt bold) and 3:1 for large text. Most legal accessibility standards worldwide — US ADA, EU EN 301 549, UK Equality Act — reference WCAG AA as the required level.
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Further reading
Authority documentation and specifications behind this tool.
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