Use a clean heading hierarchy that AI systems can turn into a table of contents
Headings should descend in order h1 → h2 → h3 without skipping levels or repeating h1.
What this signal tests
We walk every heading on the page in document order and verify that each one is the same level as, one less than, or only one greater than the previous heading. We also confirm the page has one to three h1 headings, and that very few headings are generic placeholders like "Section 1" or "Untitled".
Why it matters for your visibility in AI
AI ingestion pipelines turn your headings into a structural outline of the page, then use that outline to chunk your content for retrieval. A clean h1 → h2 → h3 hierarchy means each chunk has a clear topical anchor; jumping from h1 to h4 confuses the chunker into producing context-free fragments. Missing h1 entirely strips the page of its identity - the assistant retrieves a chunk with no title to attach it to. The concrete consequence is that AI answers cite a heading-rich, properly nested competitor instead of your page, even when your content is more authoritative. Heading hierarchy also drives the visual table of contents that some assistants display alongside citations, so a sloppy outline is a missed opportunity for free real estate.
Pass criteria at a glance
| Criterion | Passes when |
|---|---|
| Zero level-skip violations AND 1<=h1<=3 AND <=5% generic headings. |
How we test it
We extract every h1 through h6 element in document order and step through them pairwise: each subsequent heading's level must not jump by more than one. We then count h1 elements (expect one to three), and run a deny-list of generic patterns such as "section 1", "chapter 2", "untitled", and pure numeric headings. Pages with zero skip violations, one to three h1s, and fewer than five percent generic headings pass.
Show technical detection method
Walk DOM in order; for each consecutive (prev, curr) assert curr.level <= prev.level+1. Count <h1>. Flag generic deny-list (^(section|chapter|part)\s*\d+$, ^untitled$, ^[\d.\s]+$).
If your site fails: how to fix it
- Add a single descriptive h1 to every page; in WordPress and most CMSes this is the post title and is emitted automatically - confirm your theme is not also outputting the site name as h1.
- Walk through each page's headings and renumber any that skip a level: if an h2 is followed by an h4, change the h4 to h3 (or insert an h3 above it if a real sub-section is missing).
- Replace generic headings like "Section 1" or "More info" with descriptive ones that summarize the section's content; the heading is also the chunk title in AI retrieval, so make it informative.
- In page builders (Elementor, Webflow), audit headings via the outline panel rather than visually - visual size does not always match the underlying heading level.
- Avoid using heading tags purely for styling; if you need large bold text that is not a section heading, style a span or paragraph with CSS instead.
Quick facts
| Maturity | ESTABLISHED |
|---|---|
| Weight | high |
| Category | Content Clarity |
Primary sources
Related signals
Frequently asked questions
Are headings only important for SEO, or also for AI?
Both, but the mechanism differs. SEO uses headings as topical relevance signals. AI ingestion uses headings as structural anchors for chunking and as citation labels in answers. Even when classic SEO might tolerate a skipped level, AI extractors actively penalize it because their chunking logic is more literal.
Should every page have exactly one h1?
We allow one to three. HTML5 technically permits multiple h1s inside section elements, but most extractors still expect a single dominant h1. Two or three can be appropriate for landing pages with multiple distinct sections; more than three suggests the structure could be tightened.
Does the order in the HTML matter, or only the visual order on the page?
The HTML document order is what AI crawlers see. If your CSS visually rearranges sections so they look ordered to a human reader, the underlying DOM order is still what counts. Restructure the markup rather than relying on flexbox or grid to fix a broken outline.
Are h5 and h6 worth using?
Rarely. Most well-structured pages stop at h3 or h4. If you find yourself reaching for h5, the section is probably too deep and would be clearer as a new top-level section. Excessive depth is a sign that the content's organization needs reconsidering, not deeper nesting.
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