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.
  • HTML4 Legacy Techniques (Required)
  • HTML5 and ARIA Techniques (Required)
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