Color Contrast Checker
Check WCAG 2.1 color contrast ratios between any two colors for accessibility compliance — with AA and AAA pass/fail results and a live preview. It runs entirely in your browser — no data is sent to any server, no account required, and it's completely free.
The Complete Guide to Color Contrast and Web Accessibility
Web accessibility is no longer optional. With an estimated 300 million people globally living with color blindness or low vision, designing digital interfaces with proper color contrast is both an ethical responsibility and, increasingly, a legal requirement. Our free Color Contrast Checker instantly evaluates your foreground and background colors against official WCAG (Web Content Accessibility Guidelines) standards to ensure your website is readable for everyone.
What is WCAG?
The Web Content Accessibility Guidelines (WCAG) are a set of standards created by the World Wide Web Consortium (W3C). They define how to make web content more accessible to people with disabilities. The guidelines define three levels of conformance: A (minimum), AA (standard), and AAA (maximum/enhanced).
Most accessibility laws (such as the ADA in the US, or the EN 301 549 in Europe) require websites to meet WCAG 2.1 Level AA standards.
Understanding Contrast Ratios
A contrast ratio is a mathematical measurement of the difference in relative luminance (brightness) between two colors. It is expressed as a ratio ranging from 1:1 (white on white, completely illegible) to 21:1 (black on white, maximum contrast).
WCAG AA Requirements
- Normal Text (less than 18px / 14pt): Must have a minimum contrast ratio of 4.5:1.
- Large Text (18px or 14px bold): Because larger text is easier to read, the requirement drops to 3.0:1.
- UI Components and Graphics: Form inputs, buttons, and essential icons must have a contrast ratio of at least 3.0:1 against adjacent colors.
WCAG AAA Requirements
If you are designing for government portals or specialized applications for visually impaired users, you should aim for Level AAA:
- Normal Text: Requires a 7.0:1 contrast ratio.
- Large Text: Requires a 4.5:1 contrast ratio.
Common Color Contrast Mistakes
Even experienced designers frequently fail contrast checks with these common patterns:
- Light Gray Text on White: While popular in minimalist and "clean" designs, secondary text often falls well below the 4.5:1 requirement, making it invisible to older users.
- White Text on Colored Buttons: Bright primary colors (like bright orange or light blue) often do not have enough contrast with white text. You may need to darken your brand color slightly for web use.
- Placeholders as Labels: Using light gray placeholder text inside form fields instead of real labels fails contrast checks and causes usability issues.
Use our free Color Contrast tool during your design phase to catch accessibility issues early. If you need to generate WCAG-compliant color schemes, use our Color Palette Generator or convert your colors using our Color Converter.
How to Use the Color Contrast Checker
- 1
Choose Your Colors
Use the color pickers or type a hex code to set your foreground (text) color and background color.
- 2
Read the Contrast Ratio
The contrast ratio is calculated instantly. A ratio of 4.5:1 or higher passes WCAG AA for normal text.
- 3
Check the WCAG Results
See pass/fail results for Normal Text AA, Normal Text AAA, Large Text AA, Large Text AAA, and UI Components.
- 4
Preview Your Text
The live preview panel shows exactly how your text will look against your chosen background.
Frequently Asked Questions
How can I securely check WCAG color contrast ratios online for free?
Our free color contrast checker analyzes your colors 100% locally in your browser. This means you can securely test private brand colors against WCAG standards without any data leaving your device.
What color contrast ratio do I need to pass WCAG AA for free?
Using our free tool, you'll see that normal text requires a 4.5:1 ratio, while large text needs 3:1. Our browser-based checker instantly calculates these passing grades securely.
What is the difference between WCAG AA and AAA in this secure tool?
AA is the standard legal requirement, while AAA is the strict maximum level for enhanced accessibility. Our free tool securely checks your private color codes against both levels simultaneously.
How do I check UI component contrast securely without an account?
Simply enter your UI colors into our free tool. It securely checks if buttons and inputs meet the required 3:1 ratio locally, ensuring your private designs stay private.
Can I use this free tool to check contrast on background images?
Our private, free tool calculates solid colors. For images, you should test the lightest and darkest areas against your text color to ensure accessibility, all computed safely in your browser.