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Heading Structure Analyzer

Analyze the H1–H6 heading hierarchy of any page or article. Detect SEO issues like missing H1s, multiple H1s, skipped heading levels, and empty headings — all processed in your browser.

Paste your HTML
8 headings found0 errors, 0 warnings

No issues found — your heading structure looks great!

Heading Tree

  • H1How to Write Great Blog Posts
    • H2Understand Your Audience
      • H3Create Reader Personas
    • H2Structure Your Content
      • H3Use Clear Headings
        • H4Heading Hierarchy Rules
    • H2Optimize for SEO
      • H3Keyword Placement

Summary

1

H1

3

H2

3

H3

1

H4

0

H5

0

H6

8 total headings across 4 distinct levels

Why use it

Fix your heading hierarchy before you publish

Visual Heading Tree

See your entire heading structure as an indented tree. Understand parent-child relationships between H1, H2, H3, and beyond at a glance.

SEO Issue Detection

Automatically flag missing H1s, multiple H1s, skipped heading levels, empty headings, and overly long headings that hurt your SEO.

HTML & Markdown Support

Paste raw HTML to audit existing pages, or paste your draft in Markdown format. Both modes are fully supported with accurate parsing.

Instant Analysis

All analysis runs directly in your browser with zero latency. No page reloads, no API calls — just instant feedback as you type or paste.

Frequently Asked Questions

Headings help search engines understand the topic hierarchy and key points of your content. A well-structured heading outline signals quality and organization, which can improve how Google indexes and ranks your page. Proper headings also generate "jump to" links in search results, increasing click-through rates.

The ideal structure is: one H1 (the title), multiple H2s for main sections, H3s for subsections within each H2, and occasionally H4s for deeper detail. Never skip levels (H2 to H4 without an H3), and keep headings concise (under 70 characters). Think of it like a well-organized outline.

HTML5 technically allows multiple H1s when used with sectioning elements. However, Google's own SEO guidance recommends a single H1 per page for clarity. Most SEO tools flag multiple H1s as a warning, and for good reason — a single, clear H1 makes your page's topic unambiguous to both users and search engines.

The most frequent mistakes are: skipping heading levels (jumping from H2 to H4), using headings purely for visual styling instead of structure, leaving empty headings, writing headings that are too long (over 70 characters), and forgetting to include an H1 entirely. This tool catches all of these automatically.

Yes, it is completely free with no limits. All analysis runs in your browser — your HTML and text never leave your device. You can use it as many times as you want without signing up or installing anything.

Structure matters. Content matters more. Supablog writes perfectly structured posts.

Supablog's AI Writer automatically builds proper heading hierarchies, places keywords strategically, and ensures your content is readable and well-structured — so you can focus on ideas, not formatting.

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