- Success Criterion 1.4.3
- Conformance level AA
Semi-Transparent Text That Fails the Contrast Minimum
1.4.3 — Contrast (Minimum)
Scenario
Setting
A car-rental site's checkout flow
What’s wrong
Semi-transparent text/backgrounds (opacity/alpha) computing below threshold.
Example
color: #999999; background: #ffffff; /* 2.85:1 */Why it matters
Low-vision and older readers, plus anyone viewing a dim or sunlit screen.
How to test
Measure text with any opacity/alpha transparency against what's actually behind it (not the nominal color): compute the effective blended contrast.
How to fix
The text must meet at least 4.5:1 contrast (3:1 for large text) against its actual background in every state (default, hover, focus, selected). color: #595959; background: #ffffff; /* 7:1 */ Normal text needs at least 4.5:1 contrast against its background; large text needs at least 3:1.
Outcome
On a car-rental site's checkout flow, this barrier is gone for low-vision and older readers — they can complete the task without hitting this wall.
Who is affected
Low-vision and older readers, plus anyone viewing a dim or sunlit screen.
Learn more
- Understanding Understanding document (opens in a new tab)
Related scenarios
- Text Color Set Without a Matching Background Color
- Text Placed Directly Over a Photo With No Solid Backing
- Body Text Contrast That Falls Below the 4.5:1 Minimum
- Large Heading Text That Still Falls Below 3:1 Contrast
- Placeholder Text With Contrast Too Low to Read Easily
- Text on a Gradient Background Dropping Below Contrast Ratio