Color Contrast Checker
Check the contrast ratio between text and background colors to ensure your content meets accessibility standards.
What is Color Contrast?
Color contrast refers to the difference in light between text and its background. Sufficient contrast ensures content is readable by people with visual impairments.
WCAG Standards
WCAG 2.1 requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text to meet AA standards. AAA standards require 7:1 and 4.5:1 respectively.
Why It Matters
Good contrast improves readability for all users, especially those with low vision, color blindness, or who are viewing screens in bright environments.
Color Selection
Contrast Results
Normal Text
Large Text
Preview
Sample Heading
The quick brown fox jumps over the lazy dog. This is an example of how your text will look with the selected colors. Good contrast ensures readability for all users.
This is smaller text that requires higher contrast to be readable. WCAG guidelines recommend a contrast ratio of at least 4.5:1 for normal text.
Understanding Color Contrast for Web Accessibility
Color contrast is a critical aspect of web accessibility that measures the difference in luminance or color between text (or other elements) and its background. Proper contrast ensures that content is readable by people with various visual impairments, including color blindness and low vision.
The Web Content Accessibility Guidelines (WCAG) provide specific contrast requirements to ensure digital content is accessible to as many users as possible. These guidelines are organized into three levels of conformance: A (minimum), AA (mid-range), and AAA (highest).
WCAG AA Requirements
- Normal text: Contrast ratio of at least 4.5:1
- Large text (18pt+ or 14pt+ bold): Contrast ratio of at least 3:1
- UI components and graphical objects: Contrast ratio of at least 3:1
WCAG AAA Requirements
- Normal text: Contrast ratio of at least 7:1
- Large text (18pt+ or 14pt+ bold): Contrast ratio of at least 4.5:1
- Enhanced visual presentation for users with the most severe visual impairments
How to Use the Color Contrast Checker
Select Colors
Choose your text and background colors using the color pickers or by entering hex codes. You can also use the "Random Colors" button to generate accessible color combinations.
Check Results
View the contrast ratio and see if your colors pass WCAG AA and AAA standards for both normal and large text. The tool provides immediate visual feedback.
Export
Once you're satisfied with your color combination, you can copy the values or CSS code for use in your projects. The preview shows how your colors will look in a real-world context.
Benefits of Good Color Contrast
Accessibility Benefits
- Makes content readable for people with low vision
- Ensures usability for people with color blindness
- Helps users with cognitive disabilities process information
- Accommodates age-related vision changes
- Supports users with temporary vision impairments
General User Experience Benefits
- Improves readability in challenging lighting conditions
- Reduces eye strain during extended reading
- Enhances overall user experience for all visitors
- Creates more professional-looking designs
- Helps meet legal accessibility requirements
Common Color Contrast Mistakes to Avoid
Low Contrast Text
Using light gray text on a white background or dark gray on black creates insufficient contrast. Always check that your text-to-background contrast meets at least the AA standard.
Problematic Color Combinations
Some color combinations are particularly difficult for people with color blindness, such as red/green, blue/purple, and green/brown. Check your designs with color blindness simulators.
Relying Only on Color
Don't use color as the only visual means of conveying information. Always include additional indicators like patterns, icons, or text labels to ensure all users can understand your content.
Frequently Asked Questions
What is a good contrast ratio?
For most text, a contrast ratio of at least 4.5:1 is recommended to meet WCAG AA standards. For enhanced accessibility (AAA level), aim for 7:1 or higher. Large text can have slightly lower ratios (3:1 for AA, 4.5:1 for AAA).
How is contrast ratio calculated?
Contrast ratio is calculated by comparing the relative luminance of text and background colors. The formula involves converting RGB colors to relative luminance values and determining the lighter and darker colors. The ratio is expressed as (L1 + 0.05) / (L2 + 0.05), where L1 is the lighter color's luminance and L2 is the darker color's luminance.
Does font weight affect contrast requirements?
Yes. Bold text can meet accessibility standards at lower contrast ratios compared to regular or light text of the same size. This is why WCAG has different requirements for "large text" which includes text that is at least 18pt or 14pt bold.
Should I check contrast for all UI elements?
Yes, WCAG requires sufficient contrast for text and interactive elements. For non-text content like icons, buttons, and form controls, a ratio of at least 3:1 is recommended to ensure they're perceivable by users with low vision.