Techniques for WCAG 2.0

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F41: Failure of Success Criterion 2.2.1, 2.2.4, and 3.2.5 due to using meta refresh with a time-out

Applicability

HTML and XHTML

This failure relates to:

Description

meta http-equiv of refresh is often used to periodically refresh pages or to redirect users to another page. If the time interval is too short, and there is no way to turn auto-refresh off, people who are blind will not have enough time to make their screen readers read the page before the page refreshes unexpectedly and causes the screen reader to begin reading at the top. Sighted users may also be disoriented by the unexpected refresh.

Examples

Failure Example 1

This is a deprecated example that changes the user's page at regular intervals. Content developers should not use this technique to simulate "push" technology. Developers cannot predict how much time a user will require to read a page; premature refresh can disorient users. Content developers should avoid periodic refresh and allow users to choose when they want the latest information. (The number in the content attribute is the refresh interval in seconds.)

Example Code:


<html xmlns="http://www.w3.org/1999/xhtml">   
  <head>     
    <title>HTML Techniques for WCAG 2.0</title>     
    <meta http-equiv="refresh" content="60" />   
  </head>   
  <body>
    ...     
  </body> 
</html>

Failure Example 2

This is a deprecated example that redirects the user to another page after a number of seconds. Content developers are recommended to user server-side redirects instead. (The number in the content attribute is the refresh interval in seconds.)

Example Code:


<html xmlns="http://www.w3.org/1999/xhtml">   
  <head>     
    <title>The Tudors</title>     
    <meta http-equiv="refresh" content="10;URL='http://example.com/'" />   
  </head>   
  <body>
    <p>This page has moved to a <a href="http://example.com/">
    example.com</a>. Please note that we now have our own 
    domain name and will redirect you in a few seconds. Please update 
    your links and bookmarks.</p>
  </body> 
</html>

Tests

Procedure

  1. Find meta elements in the document.

  2. For each meta element, check if it contains the attribute http-equiv with value "refresh" (case-insensitive) and the content attribute with a number (representing seconds) greater than 0.

  3. check to see if there is a mechanism to turn off the refresh.

Expected Results

Techniques are Informative

Techniques are informative—that means they are not required. The basis for determining conformance to WCAG 2.0 is the success criteria from the WCAG 2.0 standard—not the techniques. For important information about techniques, please see the Understanding Techniques for WCAG Success Criteria section of Understanding WCAG 2.0.