Heading Structure (H1–H3): The Outline AI Reads

Updated June 20, 2026

When an AI reads your page, the headings are its table of contents. A clean heading structure tells it what the page is about and how the parts relate. A messy one — three H1s, a jump from H1 straight to H4, headings used only to make text big — makes the page harder to parse and quote.

The rule, in one breath

• Exactly one <h1> — the page’s main title or topic.
• <h2> for main sections, <h3> for subsections under them.
• Don’t skip levels — an <h1> shouldn’t be followed directly by an <h4>. Go in order.
• Headings are structure, not styling — never pick a heading level for how big it looks. Use CSS for size; use headings for meaning.

Good vs. tangled

A good outline reads like a sensible table of contents:

H1  Making Sourdough at Home
  H2  Ingredients
  H2  The Starter
    H3  Day 1–3
    H3  Day 4–7
  H2  Baking

Tangled versions to avoid: two <h1>s on one page, a heading level skipped for spacing, or an <h4> chosen because it “looked right.”

How to check

Open “View Source” (or your browser’s accessibility/outline view) and read just the headings, top to bottom. If they read like a coherent table of contents, an AI sees the same. If they don’t, fix the levels — not the font sizes.

The bottom line

One H1, ordered H2s and H3s, no skipped levels, chosen for meaning rather than size — that’s the whole job. It gives AI a clean outline to understand and cite. It’s one of the “be understandable” steps in our GEO overview.

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