Testing
Zoom & Magnification Testing
Test at 200% zoom (WCAG 1.4.4) and 400% zoom / 320px viewport (WCAG 1.4.10 Reflow). Check for: horizontal scrolling, overlapping text, clipped content, broken layouts, and unreadable text. Browser zoom ≠ OS magnification — test both.
In plain terms
Checking your page still works when someone enlarges it — text shouldn't overlap, get cut off, or force sideways scrolling.
Why this matters
Low-vision users routinely zoom to 200–400%. If your layout breaks, overlaps, or clips at that point you've locked out a large group — and these failures are easy to miss unless you deliberately test for them.