Free SEO tool

Heading Structure Checker

Paste your page HTML and the tool shows the heading outline and lists problems such as no H1, several H1 tags, skipped levels and empty headings.

By iToolsLab Editorial TeamUpdated 14 October 2026How we build tools

What is heading structure checker?

Headings give a page its outline. Readers scan them to find what they need, screen readers use them to navigate, and search engines use them to understand topics.

This tool extracts every heading from the HTML you paste, shows it as an indented outline and highlights structure problems.

How to use the heading structure checker

  1. Paste the HTML of the page or section.
  2. Press Check.
  3. Read the outline and fix the issues listed.

How the heading structure checker works

All h1 to h6 elements are read in order. The tool flags a missing H1, more than one H1, a first heading that is not H1, empty headings and jumps of more than one level, such as H2 followed by H4.

Worked example

A page with H1, H2, H4 and H2 shows the outline and a warning that H4 skips a level after H2.

Common uses of the heading structure checker

  • Auditing articles.
  • Checking accessibility.
  • Reviewing templates.
  • Planning content outlines.
  • Cleaning up old pages.

Tips and common mistakes

Use one H1 that matches the main topic of the page.

Use headings for structure, not for making text bigger. Use CSS for size.

Background: what to know before you rely on it

A heading outline is like a table of contents for a page. Good outlines have one top level title, main sections at the second level and details at the third. Breaking this order makes content harder to scan and can confuse assistive technology. Many themes accidentally turn widget titles or logos into headings, which creates extra H1 tags or empty headings. Checking the outline after a theme change catches these problems early.

Private, free and fast

This tool runs entirely in your browser. What you type or choose is not uploaded to a server and is not saved after you close the page, which keeps it fast and private. It is free to use as often as you like. See more in all seo tools, or browse the full list of tools.

Frequently asked questions

Can a page have more than one H1?

HTML allows it, but one H1 is clearer for users and search engines.

Do skipped levels hurt SEO?

Not directly, but they hurt accessibility and clarity.

Should headings contain keywords?

Where natural. Write for the reader first.

Does it read text from other pages?

No. Only the HTML you paste.

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Results are for information and education. For legal, financial, medical or security decisions, check with a qualified professional. Validate markup with search engine testing tools before publishing.