Timed refresh must not exist
Compliance Data & Impact
Disabilities Affected
- Deafblind
- Mobility
Requirement(s)
WCAG 2.0 (AA): MUST
WCAG Success Criteria
- 2.2.1 Timing Adjustable
- 2.2.4 Interruptions
- 3.2.5 Change on Request
Section 508 Guidelines
Not specified, or not applicable
Rule Description
The document must not use <meta http-equiv="refresh"> because it can prevent control over when the refresh occurs for users with disabilities.
Why it Matters
Since users do not expect a page to refresh automatically, such refreshing can be disorienting. Refreshing also moves the programmatic focus back to the top of the page, away from where the user had it. Such resetting is frustrating for users.
Redirection and page refresh through the use of the <meta> element is problematic for users with disabilities in many ways. The primary reason why redirects and refreshes are problematic is that the user has no control over when the redirect or refresh occurs. If the purpose of the <meta> element is to redirect the user to a new location, server-side means should be employed instead of client-side. Content that moves or auto-updates can be a barrier to anyone who has trouble reading the stationary text as quickly as well as to anyone who has trouble tracking moving objects. It can also cause problems for screen readers.
How to Fix the Problem
Remove the http-equiv="refresh" attribute from each meta element in which it is present.
To modify this example and make it accessible, remove the http-equiv="refresh" attribute from the meta element.
Bad Example
<meta http-equiv="refresh" content="10" url="http://www.yourdomain.com/index.html">If the purpose of the <meta> element is to refresh the page, this should be handled through JavaScript. Furthermore, additional scripting should be used to provide users the ability to pause the refresh, extend the time between refreshes, or to turn the refresh off entirely.
The Algorithm (in simple terms)
Checks for the presence of the http-equiv="refresh" attribute on the meta elements.