Color Contrast Checker

What is WCAG 2.1 compliance?

WCAG 2.1 (Web Content Accessibility Guidelines) is the international standard for web accessibility published by the W3C. It defines success criteria across three levels: A (minimum), AA (recommended), and AAA (enhanced). For color contrast, WCAG 2.1 requires a minimum ratio of 4.5:1 for normal text and 3:1 for large text to meet AA compliance. Most accessibility laws, including the ADA and Section 508, reference WCAG 2.1 AA as the compliance standard.

How does AI help in color contrast?

Our AI uses a TensorFlow.js machine learning model trained on over 5,000 accessible color combinations. Unlike traditional tools that only detect failures, our AI instantly suggests the closest compliant color alternatives using Delta E (CIEDE2000) color distance calculations. This ensures suggestions preserve your brand identity by finding colors that are perceptually similar to your original choice while meeting WCAG requirements. The AI analyzes hue, saturation, and lightness to recommend fixes that maintain design aesthetics.

What is WCAG and why is color contrast important?

WCAG (Web Content Accessibility Guidelines) are international standards for web accessibility. Color contrast is crucial because it ensures that text is readable for people with visual impairments, including color blindness and low vision. Proper contrast ratios make your content accessible to everyone.

What's the difference between WCAG AA and AAA standards?

WCAG AA requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text. WCAG AAA is more stringent, requiring 7:1 for normal text and 4.5:1 for large text. AA is the legal requirement in many countries, while AAA provides enhanced accessibility.

What is considered 'large text' in WCAG guidelines?

Large text is defined as 18 point (24px) and larger, or 14 point (18.5px) and larger if bold. These text sizes have lower contrast requirements because they're easier to read at lower contrast ratios.

How is this tool different from WebAIM's contrast checker?

While WebAIM's Contrast Checker is excellent for testing contrast ratios, our A11y - Smart Color Contrast Checker goes further by providing instant AI-powered fix suggestions. Instead of manually adjusting colors until you find one that passes, our tool uses machine learning to suggest the closest accessible alternatives that preserve your design intent. We also offer color blindness simulation, APCA (WCAG 3.0) scoring, and a Figma plugin integration.

Do these guidelines apply to logos and decorative elements?

WCAG contrast requirements primarily apply to text content. Logos, decorative images, and incidental text (like in photographs) are generally exempt. However, any text in images that conveys important information should meet contrast requirements.

Can I use this tool for mobile app design?

Yes! While WCAG was originally created for web content, the color contrast principles apply to all digital interfaces, including mobile apps. Many mobile platforms also reference WCAG guidelines in their Apple Accessibility and Android Accessibility documentation.