Headings must be properly nested

Rule ID Heading 5
Definition Heading elements must be properly nested on the page.
  • Heading elements that are properly nested help users of assistive technologies understand the structure of the information on the web page.
Required Yes for HTML5 and ARIA Techniques ruleset mapping
WCAG Success Criteria

1.3.1 Info and Relationships (Level A, Primary Success Criterion)

Rule Category Headings
Scope Element
Target Resources Heading elements
  • h1
  • h2
  • h3
  • h4
  • h5
  • h6
  • Include headings elements at the proper level for each section of a web page.
  • Use headings as labels for ARIA landmarks to provide a redundant way for users of assistive technologies to navigate the page (i.e. header or landmark navigation).
  • Check headings against other headings in the document to make sure they uniquely describe the content of each section of the web page.
  • If headings are too similar to each other, users of assistive technologies will not be able to use them to understand the differences between sections of the web page.
Informational Links