Text Scaling

Text scaling is the phone setting that makes words larger across apps, and a design either reflows to make room or breaks when the reader turns it up.

At the largest setting, a neat one-line label may need four lines. Rows grow taller, buttons widen, and side-by-side controls may have to stack. That is not an edge case or a rendering mistake. The giant text is the reader's chosen size, and the layout has to respect it.

The failure is easy to spot: words clipped in half, text colliding with icons, or a button whose label no longer fits inside it. Truncation that felt harmless at the default size can hide the only word that distinguishes one action from another. Responsive design handles a changing screen width; text scaling handles changing type on the same screen.

You'll also hear font scaling, large text, bigger text, accessibility sizes, and Dynamic Type, the platform name many designers use. Zoom magnifies the whole screen, including images. Text scaling grows the words and asks the layout to rearrange around them. Growing text without reflow is just a larger version of the same problem.

Try the biggest setting before calling a screen finished. If the layout only works at the designer's preferred size, it does not work for the reader who needed the setting.