• Success Criterion 1.4.3
  • Conformance level AA

Thin Font Weight Text That Fails Contrast at Small Sizes

1.4.3 — Contrast (Minimum)

Scenario

Setting

A bank's mobile money-transfer screen

What’s wrong

Thin/light font weights at small sizes measured against threshold and failing where the same hex would pass in regular weight (ratio is color-based, but teams misjudge "large text" thresholds using pt vs px).

Example

Watch a bank's mobile money-transfer screen closely and you'll spot this: thin/light font weights at small sizes measured against threshold and failing where the same hex would pass in regular weight (ratio is color-based, but teams misjudge "large text" thresholds using pt vs px).

Why it matters

Low-vision and older readers, plus anyone viewing a dim or sunlit screen. On a bank's mobile money-transfer screen, this barrier means they can't read the text against its background.

How to test

Measure thin/light-weight font text at small sizes: the same hex color that passes at regular weight can fail readability at 200-300 weight — measure the actual rendered pixels, not just the color values.

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).

Outcome

Corrected, a bank's mobile money-transfer screen now lets a visitor see the control's boundary and current state.

Who is affected

Low-vision and older readers, plus anyone viewing a dim or sunlit screen.

Learn more