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WCAG Contrast Checker - AA & AAA

Color Tools

Sample Heading

This is how body text would appear with these colors. Good contrast makes text readable for everyone, including users with low vision.

Contrast ratio

16.48:1

AA

Normal

Pass

≥ 4.5

AA

Large

Pass

≥ 3.0

AAA

Normal

Pass

≥ 7.0

AAA

Large

Pass

≥ 4.5

Large text = 18pt regular or 14pt bold. WCAG 2.1 guidelines.

What is WCAG Contrast Checker - AA & AAA?

WCAG Contrast Checker is an accessibility utility designed to verify color contrast ratios between text (foreground) and its background. Under Web Content Accessibility Guidelines (WCAG), ensuring sufficient contrast is vital for making web pages readable by visitors with visual impairments, color blindness, or varying lighting conditions. This tool calculates the exact contrast ratio instantly and rates it against the AA and AAA standards.

How it works

The tool calculates relative luminance of the foreground and background colors using the WCAG formula: L = 0.2126 * R + 0.7152 * G + 0.0722 * B, where colors are converted from sRGB to linear RGB. The final ratio (L1 + 0.05) / (L2 + 0.05) is evaluated to see if it meets the 4.5:1 (AA) or 7:1 (AAA) thresholds. All checking is performed entirely within your browser.

Features & Benefits

  • Checks WCAG 2.1 AA and AAA compliance for normal and large text
  • Live text preview shows exactly how the colors look together
  • Contrast ratio calculated entirely in your browser
  • Supports both hex input and native color picker

Frequently Asked Questions

What contrast ratio is required for WCAG AA?

WCAG AA requires a 4.5:1 ratio for normal text and 3:1 for large text (18pt regular or 14pt bold).

What is WCAG AAA?

WCAG AAA is the enhanced level: 7:1 for normal text and 4.5:1 for large text. It is recommended for maximum accessibility.

Why does contrast matter?

Low contrast makes text hard to read for people with low vision or color blindness. WCAG guidelines ensure content is accessible to the widest possible audience.

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