Level AASince WCAG 2.1
1.4.10 Reflow
Guideline 1.4: Distinguishable – Content is easy to see and hear: contrast, size, spacing.
What does the rule require?
At 320 CSS pixels wide (equal to 1280 pixels at 400% zoom) content can be read without scrolling in two directions. Exempt: content that needs two dimensions, such as data tables, maps and diagrams.
How to get it right
Build responsively with flexbox and grid, without fixed widths. Test: set the window to 1280 px wide, then zoom to 400%.
Who benefits most?
- People with low vision
Official wording
This page explains the rule in simple words. Only the original W3C text is normative.
- “Understanding Reflow” at W3C (external site)
- Techniques in the WCAG Quick Reference (external site)