Vérificateur de contraste

What Is a Color Contrast Checker?

A color contrast checker measures the luminance ratio between two colors and reports whether the combination meets WCAG accessibility guidelines. It shows the contrast ratio and whether it passes AA and AAA standards for normal and large text.

Meeting contrast requirements is essential for users with low vision or color blindness, and it's increasingly required for legal compliance in public-facing digital products.

How to Check Color Contrast

1. Select or enter your foreground color (text)
2. Select or enter your background color
3. View the contrast ratio and WCAG compliance level
4. Adjust colors if needed to meet accessibility standards

Features

• Calculate WCAG contrast ratio between two colors
• Check compliance with AA and AAA accessibility standards
• Provide suggestions for improving contrast
• Interactive color picker for easy adjustment

Common Use Cases

• Verifying that a text color on a background meets WCAG AA for web accessibility
• Checking button label contrast before publishing a UI design
• Auditing an existing design system for accessibility compliance

Why Use ToolPop Color Contrast Checker

• Checks WCAG AA and AAA compliance for both normal and large text
• Shows the exact contrast ratio so you understand how close you are to passing
• Instant feedback lets you adjust colors and re-check without leaving the page

ToolPop vs Manual WCAG Calculation

The WCAG relative luminance formula involves gamma correction and weighted channel sums that are impractical to calculate by hand. ToolPop implements the formula to the specification, reports both the ratio and the pass/fail status for every standard, and lets you iterate on color choices in real time.

Tips

• WCAG AA requires minimum 4.5:1 contrast for normal text
• WCAG AAA requires minimum 7:1 contrast for enhanced accessibility
• Dark text on light backgrounds generally provides better readability

Frequently Asked Questions

What does a contrast ratio of 4.5:1 actually mean?

It's the ratio of lighter to darker color brightness. A 4.5:1 ratio is readable by people with moderate vision loss; 7:1 is better for everyone.

Does large text have different contrast requirements?

Yes. Large text (18pt+ or 14pt bold) only needs 3:1 contrast for WCAG AA, while normal text needs 4.5:1. This accommodates readability differences.

Can I rely on this for accessibility testing?

This tool uses standard WCAG formulas, but pair it with real user testing. What works mathematically should still be tested with actual users.

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