22. Resize Text
- 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.
22.1 Test Procedure for Resize Text
Baseline Test ID: 22.1-ResizeText
All text on a page.
- 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
- Accessibility features provided by the platform or Operating System
- Controls to change text size. (If browser, operating system, or platform’s zoom function is not supported by the page, the page must provide the resize mechanism.)
- Modify the font size appearance to twice the width and height, or 200% larger.
- 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
If any of the above checks fail, then Baseline Test 22.1-ResizeText fails.
Advisory: Tips for streamlined test processes
WCAG 2.0 Techniques
The following sufficient techniques and/or common failures were considered when developing this test procedure for this baseline requirement:
- 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
- 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%