WCAG 2.1 · Level AA · Perceivable
WCAG 1.4.10 — Reflow
Content must reflow to a single column at 320 CSS pixels wide without requiring horizontal scrolling.
WCAG 1.4.10 at a glance
Level AA · Principle: Perceivable · Added in WCAG 2.1. Level AA is the conformance target for the ADA, EAA, and Section 508.
What it means
Content must reflow to a single column at 320 CSS pixels wide without requiring horizontal scrolling.
Who it helps
Low-vision users who zoom, and mobile users.
Common failures
- Fixed-width layouts forcing horizontal scroll at high zoom
- Tables/wide elements that break reflow
How to meet WCAG 1.4.10
- Use responsive, fluid layouts
- Allow content to wrap; avoid fixed pixel widths
How to test it
Manual — set viewport to 320px / zoom to 400% and check for horizontal scroll.