WCAG 1.4.4 Resize Text

Success Criterion 1.4.4 requires that text can be resized up to 200% of its default size, without assistive technology, without loss of content or functionality. It's a Level AA criterion under Guideline 1.4 (Distinguishable).

What this actually requires

A user with low vision needs to enlarge text well beyond its default size to read it comfortably. This criterion requires that when they do — via browser zoom, an OS-level text-size setting, or (on mobile) pinch-to-zoom — the page keeps working: no text gets clipped or overlapped, no controls become unusable, and critically, the user isn't forced to scroll horizontally to read each line of a normal reading column (some horizontal scrolling is acceptable for things like wide data tables, but not for ordinary paragraph text).

The most common way this fails today

On mobile, the most direct violation is a viewport meta tag that disables zooming outright:

<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">

This blocks the primary mechanism mobile users have for resizing text, regardless of how well the rest of the page would otherwise handle zoom. See Disabled Pinch-to-Zoom for the fix — removing maximum-scale/user-scalable=no entirely.

The subtler failure: layouts that break under zoom

Even without a zoom-blocking meta tag, a page built with fixed-pixel widths, absolutely-positioned text, or containers that don't reflow can still fail this criterion at 200% zoom — text may overlap other elements, get cut off by a fixed-height container, or force horizontal scrolling on what should be a simple reading column. This half of the criterion is less mechanically checkable than the viewport-meta-tag failure and benefits from an actual manual test: zoom a real page to 200% and read through it end to end.

Related but distinct: Reflow (1.4.10)

WCAG 2.1 added a related, stricter criterion — 1.4.10 Reflow — which requires content to work at 400% zoom on a 320px-wide viewport without needing to scroll in two dimensions at once. 1.4.4's 200% is the older, narrower requirement; a page that passes 1.4.10 generally passes 1.4.4 too, but the reverse isn't guaranteed.