WCAG 1.4.4: Resize Text
WCAG 1.4.4 Resize Text is a level AA success criterion from WCAG 2.0. Text can be resized up to 200 percent without losing content or function. People must be allowed to zoom.
People who need larger type lose the checkout button if zoom is disabled or the layout clips.
How to test
Zoom the browser to 200 percent. Read a product page and complete a form. Nothing essential should be cut off.
How to fix
Use relative units and remove user-scalable=no and maximum-scale=1.
Example that fails
The viewport meta tag sets maximum-scale=1, so pinch zoom does nothing.
Example that passes the check
At 200 percent zoom the add-to-basket button is still on screen and tappable.
Shopify
In theme.liquid, set the viewport to width=device-width, initial-scale=1 with no maximum-scale.
WooCommerce
Edit the theme header viewport tag and remove zoom locks.
WordPress
Remove maximum-scale from header.php.
Wix
Delete custom head code that sets user-scalable=no.