WCAG & APCA Color Contrast Checker
Check color contrast ratios against WCAG 2.1 AA and AAA criteria, evaluate APCA lightness scores, and simulate color vision deficiencies in real-time.
The WCAG & APCA Color Contrast Checker is a fast, accurate Design & Media utility designed to check color contrast ratios against wcag 2.1 aa and aaa criteria, evaluate apca lightness scores, and simulate color vision deficiencies in real-time. entirely in your browser with zero server data storage.
The Quick Brown Fox Jumps Over The Lazy Dog
This preview simulates how regular body text and headings appear under the selected vision condition. High contrast ensures readability across various ambient lighting environments and screens.
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Systems & Security Engineers • Applied Cryptography & High-Performance Web Tools
How to Use WCAG & APCA Color Contrast Checker
Pick or enter foreground & background colors
Use the color pickers or enter hex values for your text and background surfaces.
Check WCAG AA & AAA ratings
View pass/fail status for regular text (≥4.5:1), large text (≥3.0:1), and UI graphical components.
Simulate color vision conditions
Select Protanopia, Deuteranopia, Tritanopia, or Achromatopsia to verify accessibility for all users.
Frequently Asked Questions (PAA)
Related Tools & Converters
Authoritative Standards & Citations
Calculations and algorithms on this page are implemented and verified in strict accordance with the following official technical specifications:
RFC 7519: JSON Web Token (JWT)
Standardized compact, URL-safe means of representing claims to be transferred between two parties.
Web Cryptography API Specification
Standard JavaScript API for performing basic cryptographic operations in web applications.
RFC 4122: A Universally Unique IDentifier (UUID) URN Namespace
Definition of uniform format and generation algorithms for UUIDs.