Verify appropriate use of live region

Definition Verify the live region has the appropriate ARIA markup to indicate whether or how the screen reader will interrupt the user with a change notification.
Purpose
  • ARIA live regions provide a mechanism for displaying dynamic text content on a page such that changes in the content will be automatically announced to screen reader users while they are focusing on other parts of the page.
  • The manner in which informational changes in live regions are announced to screen reader users is controlled by three separate ARIA roles that may be assigned to the region: alert, log and status.
  • In general, live regions should be used sparingly, since live regions that are constantly announcing changes become distracting, and may prevent the user from completing the task they are working on.
  • A common misuse of live regions is to announce the opening of pull down menus or dialog boxes: These types of announcements are better handled through the appropriate use of other ARIA markup such as the menu and dialog roles.
Required Yes for HTML4 Legacy Techniques ruleset mapping
WCAG 2.0 Success Criteria

4.1.2 Name, Role, Value (Level A, Primary Success Criterion)

Rule Category Widgets/Scripting
Scope Element
Target Resources Elements with alert, log or status roles or the aria-live attribute
  • [aria-live]
Techniques
  • The alert role identifies a live region with very important, and usually time-sensitive, information. When the information changes in this type of live region, a message is typically sent that interrupts the current speech being spoken by a screen reader. Examples includes transaction errors that are cancelling or impeding the progress of completing a financial transaction.
  • The log role identifies a type of live region where new information is added in a meaningful order and old information may disappear. Examples include chat logs, messaging history, game log, or an error log.
  • The status role identifies a live region that contains an advisory message, but one that is not important enough to justify an alert role. This type of region is often, but not necessarily, presented as a status bar, and announcements of informational changes are typically delayed until a break occurs in the current speech being read by the screen reader software.
  • When the aria-atomic attribute is specified for a live region, it indicates to assistive technologies that when a change occurs, it should re-render all of the content or just the changes.
  • The optional aria-relevant attribute on a live region indicates what types of informational changes should be communicated to the user (e.g. additions, deletions, text and all).
  • The aria-live attribute can be used to create custom live regions, with possible values of polite, assertive and off. When used in conjunction with the ARIA alert, log or status roles, care must be taken in order to avoid conflicts with the default properties of those roles.
Informational Links