What contrast ratio is required for WCAG AAA?

WCAG AAA requires a minimum contrast ratio of 7:1 for normal body text and 4.5:1 for large text headings.

Is my data safe when using the Contrast Checker?

Yes. All computations, parsing, and transformations occur locally inside your browser via client-side JavaScript. No input data is sent to external servers.

Is the Contrast Checker completely free?

Yes. QuizOxa Tools is 100% free with no subscription, account creation, or rate limits required.

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Color Client-Side

Free Online Color Contrast Checker — QuizOxa Tools

Evaluate background and foreground color pairings to verify readability. Our contrast checker computes the relative luminance contrast ratio, comparing against World Wide Web Consortium (W3C) Web Content Accessibility Guidelines (WCAG) AA and AAA specifications.

100% In-Browser Privacy Instant Zero-Lag Execution Zero Data Uploaded

Foreground Color (Text HEX)

Background Color (HEX)

Contrast Ratio

3.96 : 1

Sample Preview Text

The quick brown fox jumps over the lazy dog.

WCAG AA Normal Text (Min 4.5:1)FAIL

WCAG AA Large Text (Min 3:1)PASS

WCAG AAA Normal Text (Min 7:1)FAIL

WCAG AAA Large Text (Min 4.5:1)FAIL

How to Use Contrast Checker

Input Your Data

Paste or type your input into the workspace above, or upload a target file directly.

Configure Settings

Select desired formatting options, conversion rules, or target units suited for your project.

Instant Processing

Execution completes in milliseconds right inside your browser memory with zero network latency.

Export & Copy

Use one-click copy to move the processed output to your clipboard or download files locally.

Key Highlights & Privacy Guarantee

Zero Server Storage

Your data is processed strictly in client-side RAM using WebAssembly and standard JavaScript APIs. No data packets or credentials are sent to our backend.

High-Speed Execution

By removing server round-trips, transformations occur in under a millisecond, optimizing Core Web Vitals and eliminating processing queues.

Free with Zero Limits

No subscription tiers, no hidden credit systems, and no registration walls. Run unlimited conversions and utilities whenever needed.

In-Depth Developer Guides

11 min read•General

WCAG Color Contrast Checker: Test AA & AAA Ratio (2027)

Test web color contrast ratios instantly against WCAG 2.2 AA & AAA standards. Free online color contrast checker for web designers and developers.

Read Full Guide

Frequently Asked Questions

Under WCAG AA guidelines, normal body text must have a minimum contrast ratio of 4.5:1, while larger headers (18pt+ or bold 14pt+) require at least 3:1.