About

Version: WCAG 2.0+
Number: 1.4.4
Level: AA
Applicability:
  • Text
Requirement:

Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality.

Guidance:

Purpose

The purpose of this success criterion is to ensure that users with varying degrees of visual impairment can enlarge the text to meet their needs.

How to Meet

Authors of reflowable EPUB publications need to ensure that they do not define font and container elements in absolute units of measure like pixels. Using flexible measures, like ems and percentages, ensures that when users change font sizes the text remains readable (e.g., it does not overlap nearby elements or get cut off by its bounding element).

This success criterion is typically not an issue for fixed layout EPUBs as reading systems allow users to zoom the content.

Additional Information

The following knowledge base pages provide more information about how to address this success criterion for publishing content: