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broken Heading Hierarchy

Heading levels should descend logically (H1 → H2 → H3), not skip levels.

notice Impact: medium WCAG 1.3.1 (Level A) HEADING_HIERARCHY_BROKEN 2 min read Updated

Why it matters

Heading levels should descend logically (H1 → H2 → H3), not skip levels. Skipping confuses screen readers and breaks the document outline.

Address when convenient — notices usually mark a polish opportunity rather than a defect. Estimated SEO impact: medium — measurable effect on click-through or relevance.

How to fix

  • Ensure every H3 is preceded by an H2 (not an H1)
  • Restructure sections so headings descend one level at a time
  • Use CSS for styling — never pick a heading level based on its visual size

Common causes

If the rule is firing across many pages, the root cause is almost always one of these:

  • Editorial team copy-pastes from another page and brings its heading levels with it.
  • Theme uses headings for visual styling rather than document structure.
  • WYSIWYG editor inserts new headings at whichever level the cursor was last on.
  • Multi-author pages stitch sections together without a single owner of the outline.

Anti-patterns to avoid

Even with the best intentions, these "fixes" make the issue worse — recognise them so you don't ship them:

  • Skipping levels (<h1> directly to <h4>) for visual styling.
  • Multiple <h1>s on one page because each section "felt like a top heading".
  • Using headings as decorative dividers without semantic content.

How atlookup detects this

Our crawler renders each page with a real headless browser, then walks the heading tree and checks for missing levels, duplicates, and skipped depths. Pages where the rule fires for broken heading hierarchy are flagged on the report.

If you'd like to see this rule fire on your own site, run a free 60-second audit — every page is reported with the exact lines that triggered it.

Tools to verify the fix

Once you've applied the fix, double-check with these external validators:

  • axe DevTools — Flags heading-order violations (a11y + SEO).
  • HeadingsMap — Browser extension that visualises the heading tree.

Frequently asked questions

Why does Broken Heading Hierarchy matter for SEO?

Heading levels should descend logically (H1 → H2 → H3), not skip levels. Skipping confuses screen readers and breaks the document outline.

How do I fix broken heading hierarchy?

Ensure every H3 is preceded by an H2 (not an H1) Restructure sections so headings descend one level at a time Use CSS for styling — never pick a heading level based on its visual size

Is this a critical SEO issue?

Address when convenient — notices usually mark a polish opportunity rather than a defect. Estimated SEO impact: medium — measurable effect on click-through or relevance.

How does atlookup detect broken heading hierarchy?

Our crawler renders each page with a real headless browser, then walks the heading tree and checks for missing levels, duplicates, and skipped depths. Pages where the rule fires for broken heading hierarchy are flagged on the report.

Does this affect accessibility?

Yes. This issue maps to WCAG 1.3.1 (Level A). Fixing it improves both SEO ranking signals and the experience for users on assistive technology.

H1_MISSING

Missing H1 Tag

The H1 is the main on-page heading — a crucial signal for Google and screen-reader users.

HEADING_EMPTY

Empty Heading Tag

An <h1>-<h6> with no text is invisible to screen readers and Google.

H1_MULTIPLE

Multiple H1 Tags on Page

While HTML5 allows multiple H1s, in practice one clear primary heading helps Google and screen readers understand the page topic.

H1_TOO_LONG

H1 Tag Is Too Long

Very long H1s (over 80 characters) get truncated in SERPs, weaken keyword focus, and make the page feel unfocused to readers.