WCAG 2.1 · Level AA · Perceivable

WCAG 1.4.4 — Resize Text, explained with examples

Text must be resizable to 200% without loss of content or functionality. Users with low vision routinely zoom to 150–200%. Fixed-pixel layouts and overflow:hidden frequently break.

Number
1.4.4
Level
AA
Principle
Perceivable
Guideline
1.4 Distinguishable

Why this criterion exists

Users with low vision routinely zoom to 150–200%. Fixed-pixel layouts and overflow:hidden frequently break.

If you only remember one thing: text must be resizable to 200% without loss of content or functionality. Everything else on this page is detail.

Who feels it when this fails

Accessibility criteria sometimes feel abstract until you see who pays the cost when a site ignores them. Resize Text affects:

  • Low-vision users

  • Older users adjusting browser zoom

How sites typically fail it

These are the patterns we see week after week. None are intentional — they are accidents of how teams build interfaces under deadline. Knowing the failure modes is the fastest path to writing them out of your component library.

  • Fixed-px layouts that overflow when zoomed

  • Modals smaller than the viewport at 200%

How to test for it

  • Zoom to 200% and verify all content and controls remain reachable.

Automated scanners catch this criterion most of the time, but never all of the time. Manual testing with the keyboard and a screen reader closes the gap.

A code fix you can copy

Use rem-based sizing so user font preferences and zoom both work.

The problem

CSS
body { font-size: 14px; }

The fix

CSS
:root { font-size: 100%; }
body { font-size: 1rem; line-height: 1.5; }

Use rem-based sizing so user font preferences and zoom both work.

Other Perceivable criteria

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