WCAG Guideline 1.4.3: Contrast (Minimum) 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 against its background.

Guideline 1.4: Distinguishable

Guideline 1.4 focuses on making content easier to see and hear. Sufficient contrast between text and background is essential for readability, especially for users with low vision or color blindness.

What Is Guideline 1.4.3 Contrast (Minimum)?

"The visual presentation of text and images of text has a contrast ratio of at least 4.5
, except for large text, incidental text, or logotypes."

Guideline 1.4.3 Contrast (Minimum) is a requirement in the Web Content Accessibility Guidelines (WCAG) .

Normal text must have a contrast ratio of at least 4.5
against its background.
Large text (18pt or 14pt bold) must have a contrast ratio of at least 3
.
Decorative or incidental text, and logos, are exempt.

For more, see the W3C's Contrast Techniques .

Why Does It Matter?

Readability: Low contrast makes text hard to read for everyone, especially those with low vision or color blindness.
Inclusivity: Ensures content is accessible to a wider audience.
Legal Compliance: Contrast (Minimum) is a Level AA requirement in WCAG 2.2.
Usability: Good contrast improves user experience for all.

What Needs to Support Accessible Contrast?

Body text and headings
Buttons and links
Form fields and labels
Images of text
Navigation menus

All must meet the minimum contrast requirements.

How to Meet Guideline 1.4.3

Use a contrast ratio checker to test text and background colors
Ensure normal text is at least 4.5
contrast
Large text (18pt/14pt bold) is at least 3
Avoid using images of text unless necessary
Test in different lighting conditions and with colorblind simulators

My tool of choice: WebAIM’s Contrast Checker .

Common Mistakes to Avoid

Using light gray text on white backgrounds
Buttons or links with insufficient contrast
Relying on color alone for emphasis
Not testing with real users or tools

Differences Between A, AA, and AAA for Guideline 1.4.3 in WCAG 2.2

Level A: No minimum contrast requirement for text (but see 1.4.1 for use of color).
Level AA: Requires 4.5
for normal text, 3
for large text.
Level AAA: Requires 7
for normal text, 4.5
for large text (see 1.4.6).

For more, see the W3C’s official documentation for 1.4.3 Contrast (Minimum) .

Quick Checklist

All text meets minimum contrast ratios
Large text meets reduced ratio
No important info in images of text
Tested with contrast checker tools

Summary

Guideline 1.4.3 ensures text is readable for everyone, especially those with low vision. Use contrast checkers and always test your designs for accessibility.

Accessibility means everyone can read your message—don’t let poor contrast get in the way!

AccessiTech LLC