WCAG Guideline 1.4.6: Contrast (Enhanced) Explained
Estimated read time: 7–8 minutes
Guideline 1: Perceivable
The Perceivable principle ensures that all users can access and understand content, regardless of their sensory abilities. This includes making sure that text is readable for users with low vision.
Guideline 1.4: Distinguishable
Guideline 1.4 focuses on making content easier to see and hear. Enhanced contrast helps users with more severe vision impairments.
What Is Guideline 1.4.6 Contrast (Enhanced)?
"The visual presentation of text and images of text has a contrast ratio of at least 7
, except for large text, incidental text, or logotypes. Large text must have a contrast ratio of at least 4.5."
Guideline 1.4.6 Contrast (Enhanced) is a Level AAA requirement in the Web Content Accessibility Guidelines (WCAG) .
- Normal text must have a contrast ratio of at least 7 against its background.
- Large text (18pt or 14pt bold) must have a contrast ratio of at least 4.5.
- Decorative or incidental text, and logos, are exempt.
For more, see CSUN: Enhancing Digital Content Visibility with Color Contrast .
Why Does It Matter?
- Accessibility: Enhanced contrast helps users with severe vision impairments.
- Inclusivity: Ensures content is accessible to the widest possible audience.
- Legal Compliance: Contrast (Enhanced) is a Level AAA requirement in WCAG 2.2.
- Usability: High contrast improves readability for everyone, especially in bright or low-light conditions.
For more, see the W3C's Contrast Techniques .
What Needs to Support Enhanced Contrast?
- Body text and headings
- Buttons and links
- Form fields and labels
- Images of text
- Navigation menus
All must meet the enhanced contrast requirements for Level AAA.
How to Meet Guideline 1.4.6
- Use a contrast ratio checker to test text and background colors
- Ensure normal text is at least 7 contrast
- Large text (18pt/14pt bold) is at least 4.5
- Avoid using images of text unless necessary
- Test in different lighting conditions and with colorblind simulators
For more, see WebAIM’s Contrast Checker .
Common Mistakes to Avoid
- Using colors that do not meet the 7 ratio for normal text
- Buttons or links with insufficient contrast
- Not testing with real users or tools
Differences Between A, AA, and AAA for Guideline 1.4.6 in WCAG 2.2
- Level A: No minimum contrast requirement for text (see 1.4.1 for use of color).
- Level AA: Requires 4.5 for normal text, 3 for large text (see 1.4.3).
- Level AAA: Requires 7 for normal text, 4.5 for large text.
For more, see the W3C’s official documentation for 1.4.6 Contrast (Enhanced) .
Quick Checklist
- All text meets enhanced contrast ratios
- Large text meets reduced ratio
- No important info in images of text
- Tested with contrast checker tools
Summary
Guideline 1.4.6 ensures text is readable for users with severe vision impairments. Use contrast checkers and always test your designs for the highest level of accessibility.
Accessibility means everyone can read your message—aim for the highest contrast!