1.4.10 Reflow
Content can be presented without loss of information or functionality, and without requiring scrolling in two dimensions, at 400% zoom (equivalent to a 320 CSS-pixel-wide viewport for content that scrolls vertically, or 256 CSS pixels tall for content that scrolls horizontally).
Last reviewed: September 9, 2026
Understanding 1.4.10
This criterion supports people with low vision who zoom their browser significantly to read comfortably, ensuring they can still scroll in a single direction rather than having to scroll both horizontally and vertically to read every line, which is exhausting and error-prone. It effectively requires that a fully zoomed desktop layout behave like a responsive mobile layout.
How to Meet It
Code Examples
.page-container {
width: 1280px; /* fixed width forces horizontal scrolling when zoomed */
}.page-container {
width: 100%;
max-width: 1280px;
display: flex;
flex-wrap: wrap;
}Frequently Asked Questions
Do wide data tables have to reflow into a single column too?
No. WCAG explicitly exempts content where two-dimensional layout is essential to understanding, such as data tables, so a wide table can still require its own horizontal scrolling without failing this criterion, as long as the rest of the page doesn't.
How does "320 CSS pixels" relate to "400% zoom"?
They describe the same test condition two ways: a typical 1280px-wide desktop viewport, zoomed to 400%, effectively shows only 320px of content at a time. Testers can either zoom a real browser to 400% or resize the viewport to 320px directly to check for reflow.
Related Success Criteria
Quick Facts
- Criterion1.4.10
- LevelAA
- IntroducedWCAG 2.1
Automate Compliance
AccessiSight automatically scans and identifies 1.4.10 issues in your codebase.
Try Scanner Free