Color Contrast Checker

What is a Color Contrast Checker?

Calculate the exact WCAG 2.1 color contrast ratio between text foreground and background colors, displaying instant AA and AAA pass/fail compliance ratings for normal text, large text, and UI components.

Why Use This Tool?

  • Accessibility (a11y) Compliance: Ensure web designs meet official WCAG 2.1 AA (minimum 4.5:1) and AAA (minimum 7:1) guidelines.
  • UI/UX Design: Test text readability over button backgrounds and card containers in dark and light themes.
  • Legal Accessibility Requirements: Avoid accessibility compliance issues by verifying color pairings.

How to Use

  1. Select or paste Text Foreground Color (HEX/RGB) and Background Color.
  2. Review real-time calculated contrast ratio (e.g. `8.5:1`).
  3. Check Pass/Fail indicators for WCAG AA and AAA standards.

Real Working Example

Input:

Text: #111827 (Dark Gray) | Background: #FFFFFF (White)

Output Result:

Contrast Ratio: 16.1:1 | WCAG AA Normal: PASS | WCAG AAA Normal: PASS | WCAG AA Large: PASS

Important Technical Details & Features

  • W3C Relative Luminance Formula: Calculates luminance using official W3C formula `(L1 + 0.05) / (L2 + 0.05)`.
  • Live Visual Preview Tile: Shows real-time text sample rendering over the background color.
  • Local Memory Execution: Zero network requests.

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Frequently Asked Questions

What is a good WCAG color contrast ratio?

WCAG 2.1 Level AA requires at least 4.5:1 for normal text and 3:1 for large text (18pt+).

What ratio is required for Level AAA?

Level AAA requires at least 7:1 for normal text and 4.5:1 for large text.

Can I test HEX and RGB color codes?

Yes, HEX, RGB, and HSL color inputs are supported.

Is it free?

Yes, 100% free.

What is the main function of Color Contrast Checker?

Check WCAG 2.1 color contrast ratios between text and background with instant AA and AAA pass/fail results. This tool validates color contrast checker structures and checks syntax correctness.

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