Heading Structure Checker
Heading Structure Checker searches pasted source for paired <h1> through <h6> elements, extracts the opening level, removes tag-looking substrings, and lists the remaining trimmed text. It is not an HTML parser: malformed markup, nested unusual content, scripts, comments, shadow DOM, client-rendered headings, and omitted closing tags can be missed or misread. It lists order but does not judge outline quality.
Runs locally — files stay on your deviceDoes this inspect a live webpage?
No. It scans only pasted HTML text.
Heading levels communicate document structure
Headings should describe sections in a meaningful hierarchy, but modern HTML outline decisions require content context rather than a simple numeric rule alone.
How it works
A global case-insensitive regex matches paired heading tags across lines; another regex strips inner tags.
Key concepts
Source, not rendered DOM
JavaScript-generated headings are absent unless pasted after rendering.
Regex limitations
HTML grammar is broader than the matching pattern.
When to use it
- Get a quick list from simple static HTML.
- Spot obvious missing or repeated levels.
- Review heading text order.
When not to use it
- Do not rely on it for malformed or dynamic DOM.
- Do not treat every level skip as automatically invalid.
- Do not use it as a full accessibility audit.
Worked examples
Simple hierarchy
- Input
<h1>Title</h1><h2>Part</h2>- Expected output
1 · Title; 2 · Part
Order is retained.
Markup inside
- Input
<h2><em>Guide</em></h2>- Expected output
2 · Guide
Inner tags are stripped.
No closing tag
- Input
<h2>Guide- Expected output
No headings found
A closing tag is required.
Common mistakes
Calling it a DOM audit
Regex scans text. Correction: Inspect the rendered accessibility tree.
Ignoring empty headings
They can appear as level-only lines. Correction: Review meaningful labels.
Treating sequence mechanically
Content hierarchy needs judgment. Correction: Map headings to page sections.
Best practices
- Paste final server-rendered or rendered HTML intentionally.
- Review one clear page topic and section hierarchy.
- Test with accessibility tools and screen readers.
Related operations and differences
Canonical Tag Generator
Choose Canonical Tag Generator when you need to generate a canonical link element from a URL.; use Heading Structure Checker specifically for heading check.
External Link Extractor
Choose External Link Extractor when you need to extract links pointing away from a hostname.; use Heading Structure Checker specifically for heading check.
FAQ Schema Generator
Choose FAQ Schema Generator when you need to generate FAQPage JSON-LD from question-answer blocks.; use Heading Structure Checker specifically for heading check.
Hreflang Tag Generator
Choose Hreflang Tag Generator when you need to generate language alternate tags from URL lines.; use Heading Structure Checker specifically for heading check.
HTML Link Extractor
Choose HTML Link Extractor when you need to extract href values from pasted HTML.; use Heading Structure Checker specifically for heading check.
Image Alt Attribute Checker
Choose Image Alt Attribute Checker when you need to find image tags missing non-empty alt text.; use Heading Structure Checker specifically for heading check.
Limitations and privacy
- Regex-based paired tags only.
- No live fetch, DOM execution, accessible-name computation, outline judgment, hidden-state check, ARIA headings, or full accessibility audit.
The pasted text or URL is processed locally in this browser and is not fetched or submitted by the tool.
Frequently asked questions
Are ARIA role headings found?
No.
Are client-rendered headings found?
Only if their rendered HTML is pasted.
Does it enforce one H1?
No.
Are malformed tags handled reliably?
No.