Techniques for WCAG 2.0

Skip to Content (Press Enter)


G204: Not interfering with the user agent's reflow of text as the viewing window is narrowed

Important Information about Techniques

See Understanding Techniques for WCAG Success Criteria for important information about the usage of these informative techniques and how they relate to the normative WCAG 2.0 success criteria. The Applicability section explains the scope of the technique, and the presence of techniques for a specific technology does not imply that the technology can be used in all situations to create content that meets WCAG 2.0.


All technologies

This technique relates to:


This technique helps avoid situations where horizontal scrolling may occur. Many people with cognitive disabilities and low vision users who do not use assistive technology have a great deal of trouble with blocks of text that require horizontal scrolling. It involves not interfering with the reflow of text if the window is narrowed. One of the best ways to do this is to define widths of text block containers in percentages.

HTML and XHTML user agents automatically reflow text as the browser window is narrowed as long as the author does not specify widths using absolute measurements such as pixels or points.


Example 1

A newspaper site includes articles with columns that adjust with the user agents window width. Users with cognitive disabilities can narrow the column to a width that makes it easier to read.


Resources are for information purposes only, no endorsement implied.



  1. Open the content that contains a block of text in a common user agent.

  2. Check to see if the user agent has a setting that needs to be enabled to allow for reflow, and if so, enable it.

  3. Narrow the viewing window to 1/4 of the screen width.

  4. Check to see that the content does not require horizontal scrolling to read a line of text.

Expected Results

If this is a sufficient technique for a success criterion, failing this test procedure does not necessarily mean that the success criterion has not been satisfied in some other way, only that this technique has not been successfully implemented and can not be used to claim conformance.