Free Online WCAG Color Contrast Checker
100% Private & No Signup Required
Free online contrast checker to ensure your color palette meets WCAG accessibility standards.
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What is Free Online WCAG Color Contrast Checker?
Check color contrast ratios between text and backgrounds to ensure your UI passes WCAG 2.1 accessibility standards and is readable by all users. Accessibility compliance is mandatory.
Poor contrast makes text unreadable for users with visual impairments or color blindness, and creates legal liability. Manually adjusting hex codes to pass WCAG thresholds is slow and error-prone.
SimpleClickLab's Free WCAG Color Contrast Checker calculates precise contrast ratios in real time using exact relative luminance formulas — all locally in your browser with zero data sent to servers.
Enter any two hex colors via the picker or paste directly. Instant pass/fail badges display compliance results for both WCAG AA (4.5:1) and AAA (7:1) thresholds for normal and large text.
A live visual preview renders how your text appears on the background color combination. Diagnostics update dynamically as you adjust either color, keeping design iteration fast.
Your corporate brand palettes, client color systems, and styling configurations remain fully private. No color data or session information is ever transmitted to external servers.
Key Features
- Real-time contrast ratio calculator based on strict WCAG 2.1 relative luminance algorithms
- Instant pass/fail badges for both WCAG AA (4.5:1 ratio) and AAA (7:1 ratio) compliance levels
- Separate diagnostics for normal text and large/bold text to prevent compliance errors
- Live visual rendering card showing an actual preview of the color combination in action
- High-speed color input system supporting raw hex code pasting and browser-native eye-dropper pickers
- 100% private and offline-capable: runs completely in-browser without server interactions
Common Use Cases
- UX/UI designers testing and validating digital brand design systems to guarantee global WCAG compliance
- Frontend developers auditing styling stylesheets during QA cycles to catch low-contrast text elements
- Product managers reviewing website designs to meet legal accessibility mandates and accessibility guidelines
- Marketing teams audit email newsletter layouts to ensure maximum readable click-through rates across devices
- Students and junior developers learning about web accessibility, relative luminance, and a11y design rules
Your data never leaves your browser
Our free WCAG Color Contrast Checker helps designers and developers ensure their websites are accessible to visually impaired users. By calculating the relative luminance between your foreground (text) and background colors, this tool instantly tells you if your combination passes the WCAG 2.1 AA and AAA standards for both normal and large text.
How to use it
Select Colors
Enter your foreground (text) and background colors using the color pickers or by pasting HEX codes.
Check the Ratio
The tool instantly calculates the contrast ratio. A higher number (e.g., 21:1) means maximum contrast.
Review WCAG Status
Look at the Pass/Fail badges for AA and AAA compliance to ensure your design meets legal and ethical accessibility standards.
FAQ
?What is a good contrast ratio?
WCAG 2.1 AA requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text. AAA requires 7:1 for normal text and 4.5:1 for large text.
?What qualifies as 'large text'?
According to WCAG, large text is defined as at least 18pt (24px) or 14pt (18.66px) if the text is bold.
?Why is color contrast important?
Good color contrast ensures that users with visual impairments, color blindness, or people viewing screens in harsh lighting conditions can still read your content comfortably.
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