What contrast ratio do I need for WCAG compliance?

WCAG 2.1 Level AA requires 4.5:1 for normal text and 3:1 for large text. Level AAA requires 7:1 for normal text and 4.5:1 for large text.

How is large text defined in WCAG guidelines?

Large text is 18pt (24px) or larger, or 14pt (approximately 18.67px) bold or larger according to WCAG 2.1 standards.

Can I test colors in different formats?

Yes, you can enter colors as HEX (#RRGGBB), RGB (rgb(r,g,b)), or use the color picker. The tool converts all formats automatically.

How is the contrast ratio calculated?

The contrast ratio uses the formula (L1 + 0.05) / (L2 + 0.05), where L1 and L2 are the relative luminance values of the lighter and darker colors.

Is WCAG compliance legally required for websites?

In many jurisdictions, yes. Laws like the ADA (US), Web Accessibility Directive (EU), and similar regulations in the UK, Canada, and Australia effectively require WCAG AA compliance.

Color Contrast Checker - WCAG AA & AAA Compliance Tool

Criterion	Required Ratio	Result
Normal Text (AA)	≥ 4.5:1
Large Text (AA)	≥ 3:1
Normal Text (AAA)	≥ 7:1
Large Text (AAA)	≥ 4.5:1
UI Components (AA)	≥ 3:1

Criterion

Required Ratio

Result

Normal Text (AA)

≥ 4.5:1

Large Text (AA)

≥ 3:1

Normal Text (AAA)

≥ 7:1

Large Text (AAA)

≥ 4.5:1

UI Components (AA)

≥ 3:1

The Color Contrast Checker is an essential accessibility tool that evaluates color combinations against WCAG 2.1 guidelines to ensure your website meets accessibility standards. This tool calculates contrast ratios between foreground and background colors, providing instant pass/fail results for AA and AAA compliance levels.

Understanding WCAG Contrast Requirements

WCAG 2.1 Level AA requires a minimum contrast ratio of 4.5:1 for normal text and 3:1 for large text (18pt+ or 14pt+ bold). For enhanced accessibility, Level AAA standards demand 7:1 for normal text and 4.5:1 for large text. The tool automatically evaluates your color combinations against both standards, clearly indicating which requirements are met.

How to Use the Contrast Checker

Enter your foreground and background colors using HEX codes (#RRGGBB), RGB values, or the built-in color picker. The WCAG contrast checker instantly calculates the contrast ratio and displays results for normal text, large text, and UI components. Visual indicators show pass/fail status for both AA and AAA compliance levels, making it easy to identify accessibility issues.

Best Practices for Color Accessibility

Always test color combinations early in your design process to avoid costly redesigns. Consider that approximately 8% of men and 0.5% of women have color vision deficiencies. Use this accessibility contrast tool to ensure your content remains readable for all users, including those using assistive technologies or viewing content in challenging lighting conditions.

This free color contrast checker streamlines accessibility compliance by providing immediate feedback on your color choices. Regular testing with this tool helps create inclusive web experiences that meet legal requirements and serve all users effectively, regardless of their visual abilities.

Color Contrast Checker - WCAG AA & AAA Compliance Tool