In older browsers, when specifying the font size with px, cm, etc. in CSS, it was sometimes impossible to enlarge or reduce characters with the browser function, so it would be better to specify the relative font sizes such as percent and em It is.
With the exception of captions and character images, text can be resized up to 200% without assistive technology without compromising content or function. "Without assistive technology" means that it is only necessary to enlarge with the browser, so web page side does not necessarily need to provide font size controller.
When enlarging the letter, make sure that the character is hidden by some element and it can not be read. Narrow inputs etc are wary of caution. It is still better to pay attention to side scrolling occurrence.
| Principle | Perceivable | Information and user interface components must be presentable to users in ways they can perceive. |
|---|---|---|
| Guideline | Distinguishable | Make it easier for users to see and hear content including separating foreground from background. |
| Criterion | Resize text (1.4.4 AA) |
With the exception of captions and character images, the text can be resized up to 200% without assistive technology without compromising the content or function. |