Free Color Contrast Checker
Check whether your text and background colors meet WCAG accessibility standards. Our Color Contrast Checker calculates the contrast ratio instantly, shows pass or fail results for AA and AAA levels, and helps you create readable, accessible interfaces.
Select Contrast Colors
WCAG Accessibility Thresholds
Normal Text (Under 18pt)
Large Text (18pt+ / Bold 14pt)
Closest Accessible Alternatives
Your selection fails basic AA text contrast. Here are mathematically calculated modifications with the minimum HSL shift to make your color pair accessible:
Text: #FFFFFF | Bg: #E60073Text: #FFFFFF | Bg: #AD0057Live Interactive Component Previews
Button Controls
Interactive Typography & Links
To learn more about compliance parameters, please read the WCAG guideline docs.
System Notification
This notification container dynamically formats foreground details against backdrop layouts.
Full Canvas Preview Simulator
Design with Accessibility in Mind.
Web Content Accessibility Guidelines (WCAG) outline design recommendations to guarantee digital readability for users with varying visual abilities. Choosing color combinations with high contrast ensures that your content is accessible, readable, and highly professional.
Evaluate Foreground and Background Contrast Instantly
Good color contrast improves readability and makes websites more accessible for everyone. This Color Contrast Checker compares foreground and background colors, calculates the contrast ratio, and evaluates compliance with WCAG accessibility guidelines.
Use it to test text, buttons, forms, icons and interface elements before publishing your website or application.
Key Features
- ✓ Instant contrast ratio
- ✓ WCAG AA compliance
- ✓ WCAG AAA compliance
- ✓ Alternative suggestions
- ✓ Button state simulator
- ✓ Input outline check
- ✓ Large & small text tests
- ✓ Color swapper
- ✓ HEX & RGB support
- ✓ Report export
- ✓ CSS variable copy
- ✓ Mobile responsive
Core Benefits
- ✓ Establish site trust and professional credibility
- ✓ Meet WCAG legal compliance guidelines
- ✓ Build inclusive interfaces for visually impaired users
- ✓ Eliminate costly design mistakes before deployment
- ✓ Elevate mobile legibility in direct sunlight
How to Test Accessibility Contrast
Evaluating color ratios is simple with our simulator:
- Enter your text color in the Foreground (Text Color) picker fields.
- Enter your background color value in the Background Color picker fields.
- Inspect the calculated contrast ratio displayed in the results widget.
- Review the pass/fail checks for AA and AAA levels.
- Adjust colors or click Apply on suggested alternatives until the indicators pass.
Accessibility Color Pairing Examples
Understanding the Contrast Ratio Formula
The contrast ratio is calculated using relative luminance, which is the perceived brightness of any point in a color space, normalized where 0 represents absolute darkness (black) and 1 represents maximum brightness (white).
Formula: Ratio = (L1 + 0.05) / (L2 + 0.05)
Here, L1 is the relative luminance of the lighter color, and L2 is the relative luminance of the darker color. The 0.05 offset accounts for ambient light flare, preventing divisions by zero on high-contrast calculations.
WCAG Compliance Levels Comparison
| WCAG Level | Normal Text (Under 18pt) | Large Text (18pt+ / Bold 14pt) |
|---|---|---|
| AA Level | 4.5:1 ratio minimum | 3.0:1 ratio minimum |
| AAA Level | 7.0:1 ratio minimum | 4.5:1 ratio minimum |
Common Accessibility Pitfalls to Avoid
- Light gray copy on white backgrounds: Frequently chosen for a 'minimalist' layout look, this is highly illegible on mobile screens.
- Red text on green backgrounds: Fails contrast standards and is completely unreadable for users with deuteranopia color blindness.
- Blue links on dark backgrounds: Default link states require careful styling to ensure contrast compliance.
- Transparent overlay text over images: Lacking solid background layers makes reading copy difficult under variable image densities.
Design Tips for Better Accessibility
- Never rely on color alone to convey meaning (such as using red text for errors; always pair it with alert icons).
- Test hover, focus, active, and disabled button states to guarantee consistency.
- Test layouts under mobile viewports in various sunlight simulations.
- Incorporate high contrast toggle buttons on dark mode selectors.
Color Blindness Considerations
Different types of color blindness (Protanopia, Deuteranopia, Tritanopia) affect how hues are perceived, often making adjacent colors indistinguishable. Color contrast checking is a universal safeguard: by ensuring a large difference in luminance (brightness) rather than relying on hue differences, you guarantee readability regardless of how colors are mapped by the eyes.
Frequently Asked Questions (FAQs)
What is color contrast?
Color contrast is the difference in light luminance between a foreground element (like text or icons) and its background. Higher contrast levels improve layout readability, helping visually impaired or color-blind users consume digital content.
What is a contrast ratio?
A contrast ratio measures the difference in relative luminance between two colors. It ranges from 1:1 (identical colors, like white on white) to 21:1 (maximum contrast, like black on white).
What is the minimum WCAG contrast ratio?
Under WCAG AA guidelines, the minimum contrast ratio is 4.5:1 for normal text (under 18pt) and 3.0:1 for large text (18pt+ or bold 14pt). Under AAA guidelines, the thresholds increase to 7.0:1 for normal text and 4.5:1 for large text.
What is the difference between AA and AAA?
AA is the mid-level compliance standard required for most corporate, commercial, and governmental websites. AAA is the highest level of accessibility compliance, required for specialised portals, education modules, or interfaces designed for senior citizens or severely visually impaired users.
How is contrast ratio calculated?
The contrast ratio is calculated using relative luminance values (L1 and L2) of both colors: (L1 + 0.05) / (L2 + 0.05), where L1 represents the lighter color and L2 represents the darker color.
Why is accessibility important?
Web accessibility ensures that all users, regardless of visual, motor, or cognitive abilities, can access online information. Furthermore, meeting accessibility targets is a legal compliance mandate in many jurisdictions globally.
Can I test button colors?
Yes! Our tool includes button, input, hover, and focus simulators so you can verify that text overlays on active control elements are completely readable and contrast-compliant.
Can I test icon colors?
Yes, WCAG 2.1 requires graphical objects and user interface components (such as icons and borders) to maintain a contrast ratio of at least 3.0:1 against their adjacent background.
What colors provide the highest contrast?
Pure black (#000000) on pure white (#FFFFFF) provides the absolute highest contrast ratio of 21:1. High-contrast pairings like dark navy on cream or emerald green on white also perform exceptionally well.
Is black on white always best?
While black text on a white background provides maximum contrast, some users with dyslexia or astigmatism find pure white backdrops harsh or blinding. Using off-white or soft cream backgrounds with dark gray text is often recommended for longer readable text.
Does font size affect contrast requirements?
Yes, because larger text characters are thicker and easier to distinguish, they require lower contrast thresholds (3.0:1 for AA) than smaller normal text blocks (4.5:1 for AA).
Is this tool free?
Yes, our WCAG Color Contrast Checker is entirely free with no registration requirements.