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Tools / 07 · Contrast Checker
Contrast Checker
Verify WCAG 2.1 contrast ratios for text and UI. Colors never leave your browser.
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Large text = ≥ 18pt (or ≥ 14pt bold). WCAG AA: 4.5:1 normal, 3:1 large. AAA: 7:1 normal, 4.5:1 large.
Frequently asked questions
- What is WCAG and why does contrast matter?
- The WCAG guidelines define minimum contrast ratios so text is readable by people with low vision or color blindness. Meeting AA (4.5:1 for normal text) is a legal requirement in many jurisdictions.
- How is the contrast ratio calculated?
- It uses the relative luminance of each color per the WCAG formula, not a simple brightness difference, which is why two colors that look similar can have very different ratios.
- Does it check large text differently?
- Yes. Large text (18pt or 14pt bold) only needs a 3:1 ratio, while normal text needs 4.5:1 and AAA needs 7:1.
- Is my input sent anywhere?
- No. Colors are evaluated locally in your browser.