Text Not Resizable

Text that is not resizable refers to content that cannot be enlarged to 200% of its original size without loss of content or functionality. WCAG Success Criterion 1.4.4 (Level AA) requires that text can be resized up to 200% using the browser's zoom or text-size settings without the need for assistive technology, and without content being clipped, truncated, or overlapping.

The most common cause of this failure is using fixed CSS units like px for font sizes, combined with fixed-height containers that cannot expand when text grows. When a container has height: 200px and overflow: hidden, any text that exceeds the container height after resizing is simply cut off. Similarly, text set in px does not respond to the browser's text-size-only zoom setting (available in Firefox and some other browsers).

Another frequent cause is viewport-unit typography (font-size: 2vw) that does not include a minimum size, making text impossibly small on mobile screens and preventing meaningful enlargement. Fixed-layout designs that do not allow text containers to grow vertically also force content overflow when text is resized.

For users with low vision, text resizing is a primary accommodation strategy. Many low-vision users do not use screen readers -- instead, they enlarge text in the browser to a size they can read comfortably. If the site prevents text from resizing or clips it when enlarged, these users lose access to the content entirely.

According to the WHO, over 1 billion people have moderate to severe distance or near vision impairment. Many of these users rely on text resizing rather than screen magnification because resizing preserves the page layout and is simpler to use. A site that breaks at 200% zoom effectively excludes this entire population.

Even users with temporary vision challenges -- fatigue, eye strain, poor lighting conditions -- benefit from the ability to enlarge text. Text resizability is a fundamental flexibility that makes content more usable for everyone.

Scrutia tests each page at 200% browser zoom and compares the visible content with the original. It detects text that overflows its container, gets clipped by overflow: hidden, or overlaps with other elements. It also flags font sizes declared in px without a rem or em fallback and viewport-based typography without a clamp() minimum.