Rule: id must be unique

Rule ID Control 5
Conformance Required
Definition All id attribute values must be unique on the page.
  • id attribute values on form control elements can be used as references by label elements. When id attribute values on the page are not unique, form controls may be incorrectly labelled.
  • aria-labelledby and aria-describedby atributes also depend on unique id values for labeling and adding descriptions to form controls.
Conformance Required
WCAG Success Criteria

Success Criterion 4.1.1 Parsing

Rule Category Forms
Rule Scope Element
  • If a form control defines an id attribute, ensure that its value is unique on the page.
Information Links