About Color Contrast Checker & WCAG Compliance
Our free online color contrast checker helps you ensure your website meets WCAG (Web Content Accessibility Guidelines) standards. Test foreground and background color combinations to verify they provide sufficient contrast for all users, including those with visual impairments.
What is Color Contrast?
Color contrast refers to the difference in luminance (brightness) between foreground elements (typically text) and background colors. The contrast ratio is calculated using the relative luminance values of the two colors, ranging from 1:1 (no contrast, like white on white) to 21:1 (maximum contrast, like black on white).
Higher contrast ratios make text easier to read for everyone, but they're especially critical for users with:
- Low vision: Including age-related vision loss
- Color blindness: Affecting approximately 8% of men and 0.5% of women
- Situational limitations: Like viewing screens in bright sunlight
- Cognitive disabilities: That affect visual processing
WCAG Accessibility Standards
The Web Content Accessibility Guidelines (WCAG) are internationally recognized standards for web accessibility, developed by the World Wide Web Consortium (W3C).
WCAG AA (Level AA - Minimum Standard)
- Normal Text: Requires a minimum contrast ratio of 4.5:1
- Large Text: Requires a minimum contrast ratio of 3:1
- Definition of Large Text: 18pt (24px) or larger, or 14pt (18.5px) bold or larger
- Compliance: Required by most accessibility laws including ADA, Section 508
WCAG AAA (Level AAA - Enhanced Standard)
- Normal Text: Requires a minimum contrast ratio of 7:1
- Large Text: Requires a minimum contrast ratio of 4.5:1
- Purpose: Provides enhanced accessibility for users with more severe visual impairments
- Recommendation: Aim for AAA when possible, especially for body text
How to Use the Color Contrast Checker
- Enter Foreground Color: Type the hex code or use the color picker for your text color
- Enter Background Color: Type the hex code or use the color picker for your background
- View Results: The tool automatically calculates the contrast ratio
- Check Compliance: See if your colors pass WCAG AA and AAA standards
- Preview: View how your colors look with actual text samples
- Adjust: Use the "Try Darker Foreground" button if colors don't pass
- Copy: Save your color values and contrast ratio for documentation
Understanding Contrast Ratios
| Ratio | Rating | WCAG Level | Use Case |
|---|---|---|---|
| 21:1 | Maximum | AAA+ | Black on white (ideal) |
| 7:1+ | Excellent | AAA | Body text, all users |
| 4.5:1+ | Good | AA | Minimum for normal text |
| 3:1+ | Acceptable | AA (Large) | Large text only |
| <3:1 | Poor | Fail | Not accessible |
Why Color Contrast Matters
Legal Compliance
- ADA (Americans with Disabilities Act): Requires accessible websites for businesses
- Section 508: Mandates accessibility for federal agencies and contractors
- European Accessibility Act: EU-wide accessibility requirements
- Lawsuits: Thousands of accessibility lawsuits filed annually
User Experience Benefits
- Readability: Easier to read for all users, not just those with disabilities
- Reduced Eye Strain: Lower fatigue during extended reading
- Mobile Usage: Better visibility in various lighting conditions
- Aging Population: Accommodates age-related vision changes
Business Benefits
- Wider Audience: Reach 15% more users (those with disabilities)
- SEO Advantages: Search engines favor accessible websites
- Brand Reputation: Demonstrates commitment to inclusivity
- Risk Mitigation: Reduces legal liability
Best Practices for Color Contrast
Choosing Colors
- Start with High Contrast: Use dark text on light backgrounds or vice versa
- Avoid Gray on Gray: Low-contrast combinations are hard to read
- Test Brand Colors: Ensure your brand palette meets standards
- Consider Dark Mode: Test both light and dark themes
- Use Color Wisely: Don't rely solely on color to convey information
Common Mistakes to Avoid
- Light Gray Text: #999 on white fails AA standards
- Colored Text on Colored Backgrounds: Often insufficient contrast
- Transparent Overlays: Can reduce contrast unpredictably
- Gradient Backgrounds: Contrast may vary across the gradient
- Image Text: Background images can make text unreadable
Testing Recommendations
- Test Early: Check contrast during the design phase
- Test All States: Verify hover, focus, and active states
- Test Real Content: Use actual text, not just lorem ipsum
- Test on Devices: Check on actual phones and tablets
- Test with Users: Get feedback from people with visual impairments
Color Contrast Formula
The contrast ratio is calculated using the relative luminance of the two colors:
Contrast Ratio = (L1 + 0.05) / (L2 + 0.05) Where: - L1 = relative luminance of the lighter color - L2 = relative luminance of the darker color - Luminance ranges from 0 (black) to 1 (white) Relative Luminance Formula: For RGB values (0-255), convert to sRGB: - If R/255 <= 0.03928: R_sRGB = R/255 / 12.92 - Else: R_sRGB = ((R/255 + 0.055) / 1.055) ^ 2.4 (Repeat for G and B) L = 0.2126 * R_sRGB + 0.7152 * G_sRGB + 0.0722 * B_sRGB
Tools and Resources
- Browser Extensions: Install accessibility checkers for continuous testing
- Design Tools: Figma, Sketch, and Adobe XD have built-in contrast checkers
- Color Palette Generators: Tools that create accessible color schemes
- Screen Readers: Test with NVDA, JAWS, or VoiceOver
- Automated Testing: Use axe, WAVE, or Lighthouse for comprehensive audits
Frequently Asked Questions
Do I need to meet WCAG standards?
While not legally required for all websites, WCAG compliance is mandated for government sites, educational institutions, and businesses in many jurisdictions. Even if not required, it's a best practice that benefits all users and protects against legal risk.
What about UI components and graphics?
WCAG 2.1 introduced Success Criterion 1.4.11 for non-text contrast, requiring a 3:1 ratio for UI components and graphical objects. This includes buttons, form inputs, focus indicators, and meaningful graphics.
Can I use color alone to convey information?
No. WCAG Success Criterion 1.4.1 states that color should not be the only visual means of conveying information. Always provide additional cues like text labels, patterns, or icons.
What about logos and decorative elements?
Logos and purely decorative elements are exempt from contrast requirements. However, if text is part of your logo and conveys important information, it should meet contrast standards.
How do I handle hover and focus states?
All interactive states must meet contrast requirements. Focus indicators specifically need a 3:1 contrast ratio against adjacent colors (WCAG 2.4.11). Test all states separately.
Related Accessibility Tools
- Color Blindness Simulator: See how your colors appear to colorblind users
- Color Palette Generator: Create accessible color schemes automatically
- Text Size Calculator: Determine if your text qualifies as "large"
- ARIA Validator: Check semantic HTML and ARIA attributes
Privacy & Security
All contrast calculations are performed locally in your browser. No color data or information is sent to our servers, ensuring complete privacy for your design work.