Color Accessibility Checker - WCAG Contrast Ratio Compliance Tool

Check color accessibility compliance with WCAG 2.1 AA/AAA standards. Free contrast ratio calculator, color blindness simulator, and accessibility testing tool for inclusive web design.

Last updated: 1/26/2025

Foreground Color (Text)

Background Color

WCAG Level & Text Size

Color Blindness Simulation

Accessibility Results

21.00:1
Contrast Ratio
✓ PASSES WCAG AA
Sample Text
This is how your text will appear with the selected colors. Make sure it's easily readable for all users.
Required Ratio
4.5:1
Current Ratio
21.00:1
Status
PASS

Understanding WCAG Accessibility

WCAG Compliance Levels

WCAG AA (Standard)

4.5:1 for normal text, 3:1 for large text. This is the legal requirement for most accessibility laws and should be your minimum target.

WCAG AAA (Enhanced)

7:1 for normal text, 4.5:1 for large text. Provides the highest level of accessibility but may be challenging to achieve in some designs.

Color Blindness Facts

  • • 8% of men and 0.5% of women have color vision deficiency
  • • Red-green color blindness is most common
  • • Never rely on color alone to convey information
  • • Use patterns, icons, or text labels alongside color
  • • Test your designs with color blindness simulators

Frequently Asked Questions

What is WCAG and why is color accessibility important?

WCAG (Web Content Accessibility Guidelines) are international standards for web accessibility. Color accessibility ensures people with visual impairments, including color blindness affecting 8% of men and 0.5% of women, can use your website effectively. It's also legally required in many jurisdictions.

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

WCAG AA requires a contrast ratio of 4.5:1 for normal text and 3:1 for large text. WCAG AAA is stricter, requiring 7:1 for normal text and 4.5:1 for large text. AA is the legal standard for most accessibility laws, while AAA provides enhanced accessibility.

How do I calculate color contrast ratios?

Contrast ratio is calculated as (L1 + 0.05) / (L2 + 0.05), where L1 is the relative luminance of the lighter color and L2 is the relative luminance of the darker color. Our tool calculates this automatically and shows whether your colors pass WCAG standards.

What types of color blindness does the simulator show?

Our simulator shows the four main types: Protanopia (red-blind), Deuteranopia (green-blind), Tritanopia (blue-blind), and Monochromacy (complete color blindness). This helps you ensure your design works for users with different types of color vision deficiencies.

What text sizes are considered 'large text' for accessibility?

Large text is defined as 18pt (24px) and above for regular weight, or 14pt (18.7px) and above for bold text. Large text has more relaxed contrast requirements because it's easier to read even with lower contrast.

Can I test multiple color combinations at once?

Yes! Use our bulk testing feature to check multiple foreground/background combinations simultaneously. You can upload your brand colors or design system colors and get a comprehensive accessibility report for all combinations.

Related Tools