What is measured
The audit extracts every h1 and flags either a missing main heading or several competing ones.
Structure and on-page signals
Single main H1
This check counts visible H1 elements and confirms that the page clearly names its primary topic.
Pass criterion
The page has one meaningful H1 aligned with the title and opening content.
What to fix
Add a missing H1 or retain one main heading and move secondary headings to h2 or h3.
Automation limit
Multiple H1 elements are valid HTML, but one main heading usually makes the structure clearer for people and analysis tools.
Reference