Color Contrast Checker
ReadyCalculate the WCAG contrast ratio of two colors for free; check AA and AAA text thresholds with a preview.
All tools are free to use. File size and processing limits may vary by tool.
Contrast ratio:
AA · Normal text (≥ 4.5:1)
AA · Large text (≥ 3:1)
AAA · Normal text (≥ 7:1)
AAA · Large text (≥ 4.5:1)
AA · UI components and graphics (≥ 3:1)
Large text: at least 18 pt (24 px), or 14 pt bold (about 18.67 px).
Preview
Can you read this text comfortably?
Can you read this text comfortably?
How to use
Choose two colors or enter HEX codes. Swap them to try the reverse theme. The black/white option selects whichever of those two provides higher contrast against the background.
Calculation runs in your browser. Decisions use the unrounded ratio. This color-pair test alone does not establish WCAG compliance; image backgrounds and transparency are not evaluated.
Web Accessibility: WCAG, ARIA and Inclusive DesignHow to use
Choose two colors or enter HEX codes. Swap them to try the reverse theme. The black/white option selects whichever of those two provides higher contrast against the background. Calculation runs in your browser. Decisions use the unrounded ratio. This color-pair test alone does not establish WCAG compliance; image backgrounds and transparency are not evaluated.
Browser tools keep files on your device. Advanced document tools upload files for temporary server processing; the tool shows this before upload. Web lookups send queries to the server and public lookup services.
Practical articles on this topic
White Text on a Green Button: Measure Before Choosing
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Dark Mode Implementation Guide: CSS, JavaScript and System Preference
Dark mode reduces eye strain and extends battery life.
Web Accessibility: WCAG, ARIA and Inclusive Design
Web accessibility ensures that people with disabilities can use websites.
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