About Color Contrast Checker
Color Contrast Checker Calculator: Ensure Your Web Design is Accessible
Our free Color Contrast Checker Calculator helps web developers and designers ensure their color combinations meet accessibility standards. This tool checks the contrast ratio between text and background colors according to Web Content Accessibility Guidelines (WCAG), making your content more accessible to users with visual impairments.
Why Color Contrast Matters in Web Development
Adequate color contrast is essential for readability and accessibility. Low contrast makes text difficult to read, especially for users with visual impairments like color blindness or low vision. Meeting WCAG contrast standards ensures your website is usable by all visitors and helps you comply with accessibility regulations.
WCAG Compliance
Our calculator checks against WCAG 2.1 guidelines, which specify minimum contrast ratios for text at different sizes and compliance levels (AA and AAA).
Instant Visual Preview
See a real-time preview of how your color combination appears, helping you make informed design decisions quickly.
WCAG Contrast Requirements
| Compliance Level | Normal Text | Large Text |
|---|---|---|
| WCAG AA | 4.5:1 or higher | 3:1 or higher |
| WCAG AAA | 7:1 or higher | 4.5:1 or higher |
Note: “Large Text” refers to text that is at least 18pt (24px) or 14pt (18.66px) bold.
How To Use This Color Contrast Checker
Our calculator makes checking color contrast simple and intuitive:
1. Set Your Colors
Choose your background and text colors using either the color picker or by entering a hex color code (e.g., #FFFFFF for white).
2. Check the Contrast
Click the “Check Contrast” button to calculate the contrast ratio and see if your colors pass WCAG requirements.
3. Review the Results
The calculator will show you the contrast ratio and indicate whether your color combination passes different WCAG levels for both normal and large text.
Benefits for Web Developers
Better User Experience
Ensuring adequate contrast improves readability for all users, not just those with visual impairments.
ADA Compliance
Meeting WCAG standards helps your website comply with accessibility laws like the Americans with Disabilities Act (ADA).
Expanded Audience
Accessible design ensures your content reaches the widest possible audience, including the 1 in 12 men and 1 in 200 women who have color vision deficiency.
SEO Benefits
Accessibility improvements can positively impact your search engine rankings, as search engines increasingly value user-friendly websites.
Understanding Contrast Ratio
The contrast ratio is calculated using the relative luminance of text and background colors. The formula compares the lighter color’s luminance (L1) to the darker color’s luminance (L2): Contrast Ratio = (L1 + 0.05) / (L2 + 0.05)
This results in a ratio ranging from 1:1 (no contrast) to 21:1 (black on white). Higher ratios mean better contrast and improved readability.
Frequently Asked Questions
WCAG AA is the minimum recommended standard for accessibility, while AAA represents enhanced accessibility. AA compliance is generally considered sufficient for most websites and is often required by accessibility laws. AAA provides superior accessibility but can be more restrictive for designers.
This calculator works with solid colors. For gradient backgrounds, it’s recommended to check contrast against the lightest part of the gradient when using dark text, or the darkest part when using light text, to ensure the worst-case scenario passes.
If you need to maintain certain brand colors, consider these approaches:
• Use your brand colors for larger graphical elements and adjust text colors for better contrast
• Add subtle backgrounds behind text to improve contrast
• Increase text size or font weight when using brand colors for headers
• Reserve low-contrast combinations for decorative elements that don’t convey information
To implement your color combinations in CSS, use:
color: #000000; for text color
background-color: #FFFFFF; for background color
You can also use these properties with RGB/RGBA format:
color: rgb(0, 0, 0);
background-color: rgba(255, 255, 255, 1);
Yes, WCAG guidelines apply to all web content regardless of the device. In fact, good contrast is even more important on mobile devices, where screens may be smaller, glare can be an issue, and users might view content in various lighting conditions.