Heading Structure Analyzer

What it does

This analyzer pulls every <h1> to <h6> heading out of HTML you paste and draws them as an indented outline, so you can see the shape of the page at a glance. It then flags three things: a missing H1, more than one H1, and skipped levels where the outline jumps down more than one step, such as an H2 followed directly by an H4. A summary line counts the headings at each level. Nothing is fetched or uploaded: the tool works only on the HTML you provide.

How to use it

1. Get the page's HTML. View source gives you what the server sends; for headings added by JavaScript, copy the rendered element from your browser's developer tools instead.
2. Paste it into "Paste HTML content or URL source".
3. Click "Analyze Headings".
4. Read the outline, then the issues box. Empty headings appear as "(empty)".

What the flags mean

A skipped level is flagged only when the outline goes deeper by more than one step. Moving back up, from an H4 to an H2, is normal and not flagged. The W3C accessibility guidance on headings advises against skipping ranks because screen reader users navigate by them, which is a good reason to fix these. The multiple H1 flag is a house style check rather than a rule: HTML allows it, and Google has said more than one H1 is not a problem for Search. A single clear H1 is still the easiest structure to read.

Headings that wrap across several lines of source, or carry attributes such as a class or id, are still found, and their text is shown on one line. Headings written in Markdown are not detected, and the tool does not judge heading wording or length.

Related guide: Heading Level Skips: How to Fix Heading Hierarchy