Baseline for Documents

22. Resize Text

Accessibility Requirements

• WCAG SC 1.4.4 Resize text – Except for captions and images of text, text can be resized without assistive technology up to 200 percent without loss of content or functionality.

Test Method Rationale

This baseline test requires an evaluation of visual content and functionality after text has been resized.

Limitations, Assumptions, or Exceptions

• Exception: captions and images of text are not included in the test.

22.A Test Procedure for Resize Text

Baseline Test ID: 22.A-ResizeText

Identify Content

All text on a page.

Test Instructions

1. Check that there is a mechanism to resize, scale, or zoom in on the content at least to 200% of original size. [SC 1.4.4]
   Known approaches include:
   • Browser zoom function or text-sizing feature
   • Accessibility features provided by the platform or Operating System
   • On-page controls to change text size.
2. Modify the font size appearance to twice the width and height, or 200% larger.
3. Check for all of the following [SC 1.4.4]:
   • Text is not clipped, truncated, or obscured
   • Text entered in text-based form controls resize fully
   • All functionality is available
   • All content is available

Test Results

If any of the above checks fail, then Baseline Test 22.A-ResizeText fails.

Advisory: Tips for Streamlined Test Processes

None

WCAG 2.2 Techniques

The following sufficient techniques and/or common failures were considered when developing this test procedure for this baseline requirement:

• F69: Failure of Success Criterion 1.4.4 when resizing visually rendered text up to 200 percent causes the text, image, or controls to be clipped, truncated, or obscured
• F80: Failure of Success Criterion 1.4.4 when text-based form controls do not resize when visually rendered text is resized up to 200%
• F94: Failure of Success Criterion 1.4.4 due to incorrect use of viewport units to resize text
• G178: Providing controls on the Web page that allow users to incrementally change the size of all text on the page up to 200 percent
• G179: Ensuring that there is no loss of content or functionality when the text resizes and text containers do not change their width