The criterion behind it
1.4.4 Resize Text
Text has to survive being zoomed to 200% without losing content or function.
Level AA · EN 301 549 § 9.1.4.4
Why this check exists
Zoom is the most common accommodation there is, and the one most designs quietly break.
What usually triggers it
- failsFixed-height containers that clip text when it grows.
- fails`user-scalable=no` in the viewport meta tag.
- failsFont sizes in `px` inside a layout that never reflows.
How to fix it
- doRemove `user-scalable=no` and `maximum-scale`.
- doLet containers grow: `min-height` instead of `height`, and no `overflow: hidden` on text.
- doTest at 200% browser zoom, which is not the same as a narrow viewport.
How it is reported
A11ySignal reports this at critical impact. Every failing element comes with its CSS selector and the markup that failed, so you can go straight to the line rather than hunting for it. Deque publishes the engine-level detail:
https://dequeuniversity.com/rules/axe/4.13/meta-viewport ↗
Check implemented by axe-core 4.13.0, © Deque Systems, MPL-2.0.