Heading Structure Analyzer
Analyze H1-H6 heading hierarchy from HTML or Markdown. Detect SEO issues, visualize the outline, and score your structure.
Updated
Source Input
SEO Score
Frequently Asked Questions
What is the Heading Structure Analyzer?
The Heading Structure Analyzer is a free online tool that analyze h1-h6 heading hierarchy from html or markdown. detect seo issues, visualize the outline, and score your structure.. It runs entirely in your browser with no installation or sign-up needed.
How does it work?
Paste HTML or Markdown and the tool parses h1-h6 (or # levels) entirely in your browser to build an outline, detect issues, and score the structure.
Why avoid skipping heading levels?
Jumping H1 → H3 breaks the document outline that screen readers and search engines rely on to understand hierarchy. Always step one level at a time.
How many H1 tags per page?
Exactly one. A single H1 describes the main topic; all other sections should use H2 and below.
Is the Heading Structure Analyzer free to use?
Yes, the Heading Structure Analyzer is 100% free with no registration, no hidden fees, and no usage limits. All processing happens locally in your browser, ensuring complete privacy.
Is my data safe with this tool?
Absolutely. The Heading Structure Analyzer processes everything client-side in your browser. No data is uploaded to or stored on any server. Your content remains private on your device at all times.
Does the Heading Structure Analyzer work on mobile devices?
Yes, the Heading Structure Analyzer is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.
Do I need to create an account to use this tool?
No account or registration is needed. Simply open the Heading Structure Analyzer in your browser and start using it immediately. There are no sign-up walls or usage restrictions.
Does this tool follow Google's latest guidelines?
Yes, the Heading Structure Analyzer is built following current Google Search guidelines and best practices. We regularly update the tool to reflect changes in search engine requirements.
How do I use the Heading Structure Analyzer?
Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.
What is the difference between an H1 tag and the page title tag?
They look similar but live in different places and do different jobs. The title tag sits in the page's <head> and is what shows as the clickable headline in search results and the browser tab — it is metadata, not visible body content. The H1 is an on-page heading inside the <body> that readers actually see at the top of your content, describing the main topic of that page. A page should have exactly one H1, just as it has one title tag, and the two often share similar wording but do not need to match word for word. This analyzer only reads body headings (H1 through H6), so it checks your H1 rather than your title tag — paste your HTML and it will flag a missing or duplicate H1 right away.
What is the difference between H2 and H3 headings?
H2 and H3 mark different levels of the same content hierarchy. H2 headings define the main sections of a page that sit directly under your single H1, while H3 headings break those sections into smaller subsections nested beneath a specific H2. Think of it like an outline: H1 is the title, each H2 is a chapter, and each H3 is a sub-point within that chapter. The key rule is order — an H3 should always follow an H2, never jump straight from an H1, because skipping a level confuses both search engines and screen readers reading the outline top to bottom. Paste your HTML or Markdown here and the analyzer renders the H2/H3 nesting as an indented outline and tree view, flagging any skipped levels so you can see the hierarchy at a glance.
Why does heading structure matter for SEO?
Headings are the skeleton search engines use to understand how a page is organized and what each section covers. A clean, logical H1 to H6 hierarchy helps Google identify the main topic and pull the right passage for featured snippets and AI overviews, while a broken outline makes content harder to interpret. Headings matter for accessibility too: screen-reader users navigate by jumping heading to heading, so skipped levels or a missing H1 create a genuine barrier. Good structure also improves scannability, keeping readers engaged longer. This tool checks your headings against established rules — one H1, no skipped levels, no empty or overly long headings — and gives a score out of 100 so you can confirm the structure reads cleanly to crawlers, assistive technology, and people alike. Paste your markup to see where it stands.
What does the heading structure score out of 100 mean?
The score is a quick health signal for your outline, not a Google ranking. It starts at 100 and subtracts points for each problem the analyzer finds: 25 points for every critical issue like a missing or duplicate H1, 8 points for each warning such as a skipped level, empty heading, or a heading over 70 characters, and 3 points for info-level notes like duplicate heading text. The total is clamped between 0 and 100, so a page with several critical faults can bottom out at zero. The weighting reflects real impact — a missing H1 hurts far more than one heading running a few characters long. Use the score to compare drafts and verify that a fix actually moved the needle. Paste your HTML or Markdown to get an instant score with a full breakdown of every issue by severity.
Can this tool analyze headings from Markdown as well as HTML?
Yes. The analyzer has two input modes. In HTML mode it parses your markup with the browser's own DOMParser and pulls every H1 through H6 tag from a full document or a fragment. In Markdown mode it reads the text line by line, treating one to six hash marks (# through ######) as heading levels one to six, and it deliberately skips fenced code blocks so a # comment inside code is never mistaken for a heading. Both modes feed the same outline view, tree view, table of contents, issue checks, and score, so you get identical analysis whichever format your content lives in. That makes it handy whether you are auditing a published page's source or a draft written in Markdown. Switch between the HTML and Markdown tabs, paste your content, and the headings parse instantly in your browser.
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About the Heading Structure Analyzer
The Heading Structure Analyzer takes the HTML or Markdown behind a page and rebuilds its heading outline so you can see, at a glance, whether the H1–H6 hierarchy actually makes sense. Paste a full HTML document, an HTML fragment, or Markdown (# through ######), and the tool extracts every heading, lays them out as a nested outline, flags structural problems, and gives the result a score out of 100. It's built for SEO specialists, content editors, technical writers, and developers who care that a page reads as a clean document — not just to humans, but to search engines and screen readers.
Everything runs in your browser. The HTML is parsed locally with the browser's own DOMParser, and Markdown is read line by line (fenced code blocks are skipped so # comments inside code don't get mistaken for headings). Nothing is uploaded, there's no sign-up, and there are no usage limits — you can paste an unpublished draft or a competitor's source and it never leaves your device.
What the analyzer checks
The tool runs your headings against a set of well-established structural rules and sorts findings into three severity levels — critical, warning, and info:
- Missing or duplicate H1 — every page should have exactly one H1 describing its main topic. No H1, or more than one, is flagged as critical.
- Skipped levels — jumping from H2 straight to H4, for example, is flagged as a warning. Headings should descend one step at a time.
- Empty headings — heading tags with no text content.
- Overly long headings — anything past 70 characters is flagged, since long headings hurt scannability.
- Duplicate heading text — identical headings that could confuse the outline or an anchor-based table of contents.
- Structural gaps — using only H1s, or having no H2s at all, when a page clearly needs sub-sections.
How the score works
The score starts at 100 and subtracts points per issue: 25 for each critical problem, 8 for each warning, and 3 for each info-level note, with the result clamped between 0 and 100. That weighting reflects real-world impact — a missing H1 damages a page far more than one heading that runs a few characters long. The score is a quick health signal, not a Google ranking; use it to compare drafts and confirm that fixes actually moved the needle.
Ways to view and export your outline
Beyond the issue list, the analyzer presents your headings several ways so you can work the way you prefer:
- Outline — an indented, navigation-pane-style view where each heading is tagged with its level (H1, H2, …).
- Tree view — a monospace ASCII tree that's easy to drop into notes or a ticket.
- Table of contents — a ready-made anchor list, with each heading slugified into a linkable ID.
- Stats — total headings, average heading length, a per-level breakdown of how many H1s through H6s you used, plus the longest and shortest headings.
When the structure looks right, you can copy a clean Markdown outline, copy an HTML nested list, download the outline as a .md file, or export every detected issue as a CSV to share with a team.
Why heading structure matters for SEO
Headings are the skeleton of a page. Search engines use them to understand what each section covers and how content is organized, and a logical hierarchy helps Google pull the right passages for featured snippets and AI overviews. Just as importantly, assistive technology relies on heading levels for navigation — a user with a screen reader jumps heading to heading, so a broken outline is a genuine accessibility barrier. Getting the structure right with the Heading Structure Analyzer makes a page easier to crawl, easier to read, and easier to navigate, all at once.