Accessibility rule: Field input error is not announced in full, explained

Most of us have experienced trying to complete a poorly designed online form. Sometimes the information entered is incorrect, and it's difficult to understand where the problem is. This is a frustrating experience for anyone and a real barrier for users with cognitive or visual impairments.

When filling out a form, all users need to understand the information required for each input field. If for instance, a user types a date in the wrong format, they should be made aware of the specific error. This ensures that users know immediately that the information they have entered is in the wrong format.

Who is impacted by this barrier?

This rule checks that field input error messages are announced in full by screen readers.
When the page content changes, sighted users can often see that immediately. On the other hand, screen readers need to be told to stop reading what they are currently reading if an error occurs. This is done using aria-live="assertive". This enables the screen reader to read the new or updated content, but the error might still lack some context. By adding aria-atomic="true", a screen reader will know to read the entire error message.

Info: “Atomic” comes from Greek and means “cannot be cut”.

How does this rule work?

The rule checks that an input field marked as aria-live="assertive" is also marked as aria-atomic="true". Read more about how the SIA-R54 rule in Alfa, Siteimprove’s open-source accessibility conformance testing engine.