ID attribute value must be unique

Who might be affected


As implied by their property name, id values should be unique regardless of their accessibility. Labeling interactable elements is an important part of accessibility and many labeling techniques use ids to make link the labeled and labeling elements. When id values are not unique it might cause confusion and misunderstanding with the UI by screen reader users.

Quick Fixes

Make sure that no interactable (focusable) element has a duplicate "id" value, and remove them if they exist.

How Users Are Affected

Screen readers will only refer to the first element with a certain id and skip each additional element with the same id. The user will therefore not receive the full content.

WCAG Success criteria

This issue might cause elements to fail one or more of the following Success criteria:
4.1.1 Parsing (A)

Recommended Reading