Color Contrast Ratio Checker

Report an Issue

Help us improve by telling us what went wrong.

Embed this Tool

Customize and copy the embed code for your website.

Ensure Your Designs Are Readable for Everyone

Accessibility is not optional - it is a legal requirement in many jurisdictions and a moral imperative everywhere else. The Color Contrast Ratio Checker calculates the contrast ratio between any two colors and tells you whether the combination meets WCAG (Web Content Accessibility Guidelines) standards for text readability. If your website or application uses color combinations that people with visual impairments cannot read, this tool helps you identify and fix those problems before they affect your users.

The WCAG defines specific contrast ratio thresholds. For normal text, the minimum ratio is 4.5:1 (Level AA) and the enhanced standard is 7:1 (Level AAA). For large text (18pt or 14pt bold), the minimum drops to 3:1 (Level AA) and 4.5:1 (Level AAA). The Color Contrast Ratio Checker evaluates your color pair against all four thresholds and clearly indicates which standards are met and which are not.

How to Check Your Color Contrast

Enter your foreground (text) color and background color using HEX codes, RGB values, or the built-in color picker. The tool instantly calculates the contrast ratio and displays a pass/fail indicator for each WCAG level. A live preview shows your text color against the background so you can see the actual readability yourself. If the ratio fails, you can adjust either color incrementally and watch the ratio update in real time until you find a combination that passes.

This iterative adjustment feature is what makes the tool genuinely useful during the design process, not just as a post-hoc audit. You can explore color options and find accessible alternatives without leaving the tool.

Why Contrast Ratios Are Non-Negotiable

Approximately 300 million people worldwide have some form of color vision deficiency. Millions more have low vision due to aging, eye conditions, or environmental factors like screen glare. When your text color does not contrast sufficiently with its background, these users literally cannot read your content. In practical terms, that means lost customers, frustrated users, and potential lawsuits under accessibility legislation like the ADA, Section 508, or the European Accessibility Act.

Even for users with perfect vision, poor contrast causes eye strain during extended reading sessions. That light gray text on a white background might look elegant in a design mockup, but it becomes painful to read in a brightly lit office. Good contrast benefits every single user.

Who Should Use This Tool?

Web designers should check every text-background combination in their designs before handoff to development. Building accessibility into the design phase is far cheaper than retrofitting it later. Frontend developers implementing designs should verify contrast ratios when the actual rendered colors might differ slightly from the design file due to CSS calculations, transparency, or theme variations.

Product managers and project leads responsible for accessibility compliance use the tool during QA reviews to verify that the delivered product meets WCAG standards. Content creators choosing colors for presentations, infographics, and social media graphics benefit from checking readability before publishing. Marketing teams designing email templates need to ensure their calls-to-action are readable across different email clients and device screens.

Common Contrast Mistakes

The most frequent violations involve placeholder text in form fields (light gray on white), secondary navigation links (medium gray on light gray), and disabled button states (subtle color differences that are invisible to many users). The tool helps you find accessible alternatives for all of these patterns.

Another common mistake is checking contrast against a solid background when the actual implementation places text over an image or gradient. In those cases, you need to test against the darkest and lightest areas of the background to ensure readability in all conditions.

Tips for Accessible Color Choices

When adjusting colors to improve contrast, prefer darkening the darker color rather than lightening the lighter one. This typically preserves the design's visual character better. If you are working with brand colors that cannot change, adjust the text color instead. Consider using a semi-transparent overlay between text and image backgrounds to guarantee minimum contrast regardless of the image content. Always test your colors in both light and dark modes if your application supports theme switching.

The Color Contrast Ratio Checker runs entirely client-side. No design data is shared with any server. It is a quick, reliable tool that should be part of every designer and developer's standard workflow.