Heading Structure Analyzer
Extract a page heading outline from HTML and flag structural SEO and accessibility issues like missing H1s, multiple H1s, or skipped levels.
Heading outline
Your result will appear here.
Issues
No structural issues found.
What is Heading Structure Analyzer?
Heading Structure Analyzer inspects HTML markup to visualize its heading hierarchy (H1 through H6) and flag structural SEO and accessibility flaws. Using browser DOM parsing, it extracts all heading elements, renders an indented outline, and detects critical issues including missing H1 tags, duplicate H1 tags, and skipped heading levels (e.g. jumping from H2 directly to H4).
How to use Heading Structure Analyzer
- 1Paste your page HTML source or template markup into the HTML input area.
- 2View the extracted heading outline with visual indentation corresponding to heading levels.
- 3Check the Issues panel for warnings regarding missing H1s, multiple H1s, or skipped hierarchy levels.
Key features
Indented Outline Visualization
Extracts H1 through H6 headings and renders an indented visual hierarchy of the page outline.
H1 Tag Verification
Checks for a missing H1 tag or flags multiple H1 tags that may confuse search crawlers.
Skipped Level Detection
Identifies non-sequential jumps in heading levels (such as H2 jumping directly to H4).
Client-Side DOM Parsing
Parses pasted HTML safely in browser memory using DOMParser without network requests.
Examples & use cases
Valid Heading Hierarchy
Sequential heading structure following logical hierarchy with a single H1.
<h1>Page Title</h1>\n<h2>Section One</h2>\n<h3>Subsection</h3>\n<h2>Section Two</h2>
Outline: H1 Page Title -> H2 Section One -> H3 Subsection -> H2 Section Two. Issues: No structural issues found.
Skipped Heading Level Issue
Skipping heading levels violates accessibility standards (WCAG) and disrupts screen reader navigation.
<h1>Main Topic</h1>\n<h4>Sub-sub topic</h4>
Issues: Heading level skips from H1 to H4 at "Sub-sub topic".
Frequently asked questions
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