Contrast Calculator

Check color contrast for WCAG accessibility online for free. Calculate contrast ratio, test AA/AAA compliance and simulate color blindness.

About Contrast and Accessibility

Color contrast is fundamental to web accessibility. Approximately 8% of men and 0.5% of women have some form of color vision deficiency. Adequate contrast ensures your content is readable for all users. WCAG Levels Minimum ratio of 4.5:1 for normal text (smaller than 18px or 14px bold) Minimum ratio of 3:1 for large text (18px+ or 14px+ bold) Minimum ratio of 7:1 for normal text - most stringent level Minimum ratio of 4.5:1 for large text - most stringent level Types of Color Blindness Deuteranopia (green-blind) and protanopia (red-blind) are the most common types. Tritanopia (blue-blind) is rarer. Testing your colors with simulations helps ensure your design works for everyone. Accessibility Tips Never rely solely on color to convey information - also use icons, text, or patterns. Test your design with different color blindness simulations. Use contrast tools during development, not just at the end.

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