WebTools
Design & UX5 min read•June 28, 2026

WCAG Accessibility Guide: How to Check Color Contrast Ratios for Web UI

Ensure web interface designs pass WCAG AA (4.5:1) and AAA (7:1) contrast standards for visual readability and accessibility compliance.

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Reviewed by the GreenCode Design & UX Editorial Desk
Last Updated: June 28, 2026
Disclaimer: Calculations and results provided by this tool are mathematical estimates for informational and educational purposes only. They do not constitute professional financial, tax, or legal advice.
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Introduction

Web Content Accessibility Guidelines (WCAG) mandate minimum contrast ratios between foreground text and background colors to assist visually impaired users.

Step-by-Step Instructions

  1. Pick Background Color and Text Color using HEX or RGB pickers.
  2. View calculated WCAG Contrast Ratio.
  3. Check AA (4.5:1) and AAA (7:1) pass/fail badges.

Key Use Cases

  • Web & App Design: Test button labels, body copy, and UI accents for readability.
  • Brand Identity: Verify primary brand color combinations before publishing design systems.

Frequently Asked Questions

What contrast ratio is required for WCAG AA compliance?

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