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warningSEO RULE · R09

Broken heading structure: H1, H2, H3 rules for SEO and accessibility

Every page needs exactly one H1 and a logical heading hierarchy (H2 sections inside the page, H3 subsections inside H2s). Crawlers and screen readers both use heading structure as a content outline.

Every page needs exactly one H1 and a logical heading hierarchy (H2 sections inside the page, H3 subsections inside H2s). Crawlers and screen readers both use heading structure as a content outline. Heading tags (<h1> through <h6>) provide the document outline. The H1 is the page's primary topic; H2s break it into sections; H3s break sections into sub-sections. The hierarchy must not skip levels (H1 → H3 with no H2 is a violation).

Last updated·part of the 50-rule library

What it is

Heading tags (<h1> through <h6>) provide the document outline. The H1 is the page's primary topic; H2s break it into sections; H3s break sections into sub-sections. The hierarchy must not skip levels (H1 → H3 with no H2 is a violation).

Why it matters

Search engines parse heading structure to understand what a page is about and what its sub-topics are — this directly informs which queries you can rank for and which sections might appear as featured snippets. For accessibility, screen reader users navigate by heading; a missing H1 means there is no main landmark to jump to.

How to fix it

  1. One H1 per page, containing the primary keyword. The H1 should be the question or topic the page answers. Multiple H1s are a holdover from poor templates — fix the template, not each page.
  2. Use H2 for top-level sections. If you can imagine a table of contents for the page, each TOC entry is an H2. Common pattern: 3–7 H2s on a long-form article.
  3. Never skip levels. Inside an H2, use H3 — not H4. Skipping levels breaks the outline. Most CMSs let editors pick any heading; teach editors to follow the hierarchy.
  4. Do not use headings for styling. If you want big bold text that is not a section heading, use CSS. Headings are structural, not decorative.

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