What is a contrast checker and why use it?

Accessibility & Usability

Sufficient contrast improves readability for everyone, especially users with low vision, color-vision deficiencies, or on low-quality displays.

WCAG 2.1 Requirements

Check 1.4.3 Contrast (Minimum), 1.4.6 Contrast (Enhanced), and 1.4.11 Non-text Contrast for UI components and graphics.

EAA / EN 301 549

The European Accessibility Act references EN 301 549 which in turn references WCAG contrast is a key part of meeting obligations.

Brand & Design Quality

Accessible palettes create resilient, legible interfaces that work in light/dark themes and across devices.

WCAG 2.1 contrast thresholds (quick reference)

Normal Text
AA

Minimum ratio: 4.5:1 (text under 24px regular / 19px bold).

Large Text
AA

Minimum ratio: 3:1 (≥ 24 px regular or ≥ 19 px bold).

UI Components & Graphics
1.4.11

Minimum contrast with adjacent colors: 3:1 (focus rings, form inputs, icons, etc.).

Understanding WCAG Color Contrast for Web Accessibility

A color contrast checker is an essential tool for web designers and developers to ensure their digital content meets accessibility standards. WCAG color contrast guidelines help create interfaces that are readable and usable by everyone, including people with visual impairments.

What is WCAG Color Contrast?

WCAG (Web Content Accessibility Guidelines) defines specific contrast ratios between text and background colors to ensure readability. The contrast checker calculates these ratios using relative luminance values, providing a mathematical measure of how distinguishable colors are from each other. Meeting these standards is crucial for WCAG 2.1 conformance and is referenced by regulations like the European Accessibility Act (EAA) through EN 301 549.

How Does a Contrast Checker Work?

Our WCAG color contrast checker analyzes the luminance difference between foreground (text) and background colors. It automatically calculates the contrast ratio and compares it against WCAG success criteria 4.5:1 for normal text (Level AA), 3:1 for large text, and 7:1 for enhanced contrast (Level AAA). This instant feedback helps you make informed design decisions without manual calculations.

Best Practices for Color Contrast

Start by testing your brand colors early in the design process using a contrast checker. Ensure all text elements, buttons, form inputs, and icons meet minimum requirements. Don't rely solely on color to convey information, use text labels, icons, or patterns as well. Regular testing with a WCAG contrast checker helps maintain accessibility standards throughout your project lifecycle.

Try the Contrast Checker

Enter foreground and background colors (HEX). The tool calculates the contrast ratio and shows pass/fail for WCAG levels. Results update as you type.

FAQ

Does WCAG 2.1 change contrast ratios?
No, the contrast thresholds remain the same as in 2.1 (4.5:1 normal text, 3:1 large text, 3:1 for non-text UI/graphics).
Does the EAA require WCAG contrast?
Yes. EN 301 549 (referenced by the EAA) incorporates WCAG 2.1 requirements, including color contrast for text and non-text elements.
What counts as 'large text'?
At least 18pt (24px) normal weight or 14pt (19px) bold, which qualifies for the 3:1 threshold.

Make contrast checks part of your workflow

Run contrast checks during design reviews and code PRs. Combine with automated scanning to catch issues at scale.

Free Color Contrast Checker – WCAG 2.2 & EAA Compliance