What is Contrast Checker?
Contrast Checker is a free browser-based color tool. All color calculations and conversions run locally in your browser. No data is sent to any server. Works with HEX, RGB, HSL and other color formats.
This tool lets you wcag color contrast ratio without installing any software or creating an account. Everything runs directly in your browser for maximum privacy. Your files and data never leave your device.
Use it for quick tasks at any time from any device — desktop, tablet or mobile. No subscription, no ads, no limits.
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Instant results
No server processing or wait
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100% private
Files stay on your device
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Always free
No subscription or fees
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Mobile ready
Works on any device
How to use Contrast Checker
- Open the Contrast Checker tool
- Enter your input data or upload your file
- Configure the settings for your use case
- Download or copy the result
Why use OnlineToolsPlus?
Color tools on OnlineToolsPlus handle all conversions and calculations locally in your browser. Convert between HEX, RGB, HSL, CMYK and CSS formats instantly. Generate palettes, gradients and accessibility contrast ratios. Whether you are designing for screen or print, the tools give you accurate color values without any account or software.
Frequently asked questions
What contrast ratio is required for accessibility?
WCAG 2.1 requires a minimum contrast ratio of 4.5:1 for normal text and 3:1 for large text (18pt or 14pt bold) to meet AA compliance. AAA compliance requires 7:1 for normal text.
What is WCAG?
The Web Content Accessibility Guidelines are international standards for making web content accessible to people with disabilities, including those with low vision or color blindness.
How do I check if my website passes accessibility standards?
Enter your text color and background color. The tool shows the contrast ratio and indicates whether it passes WCAG AA and AAA levels.
My design fails contrast requirements. How do I fix it?
Darken the text color, lighten the background, or both. Small adjustments to lightness in HSL can often achieve compliance without significantly changing the visual design.
Does it work offline?
Yes.
Does contrast ratio apply to icons and non-text elements?
WCAG has a 3:1 ratio requirement for UI components and graphical objects needed to understand content. This is a lower bar than text requirements.
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Last updated: April 11, 2026
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