H1 Singularity
H1 singularity is the convention that each page should have exactly one H1 element — the page's primary heading — with subsequent headings using H2, H3, and so on in proper hierarchy.
In context
Modern HTML5 technically allows multiple H1s with sectioning elements, but search engines and accessibility tools still treat the first H1 as the primary heading and treat additional H1s with skepticism. Practical guidance: one H1 per page, mirroring or closely matching the title tag, describing the page's primary topic. Use H2 for major sections, H3 for sub-sections, etc. A flat heading structure (H1 → H2 → H2 → H2) is healthier than skipping levels (H1 → H4).
A Canadian publisher's audit found 18% of pages with multiple H1s (typically because logo or hero section was marked H1); fixing the templates to use a single semantic H1 produced cleaner Search Console reporting and small ranking improvements.
Have a question this didn't answer?
Book a free 60-minute strategy call. We'll explain how this concept applies to your specific situation.