Heading Structure Checker
See a page's heading outline and find levels that are skipped or out of order.
About this tool
Fetches a page and shows every heading in document order, indented by level, with the places where a level is skipped marked.
Headings are structure, not styling. Screen-reader users navigate a page by jumping between them, so an H2 followed by an H4 leaves a gap in the outline they rely on. It is invisible to anyone reading with their eyes, which is exactly why it goes unnoticed — the usual cause is picking a heading level because the font size looked right.
Common questions
Can a page have more than one H1?
HTML5 allows it and it is not an error. One H1 still states the page topic more clearly than several competing ones, so it remains the safer default.
Why does skipping a level matter?
Screen-reader users navigate by heading level. Going from H2 straight to H4 tells them a level exists that they never encountered, which makes the page harder to move through. Sighted readers see nothing wrong, so it survives review.
Should I use headings to control size?
No — that is what CSS is for. Pick the level that describes where the section sits in the document, then style it to whatever size looks right.
Do headings affect rankings?
Not as directly as people assume. They help a search engine understand a page's structure, and they matter a great deal for accessibility. Write them for the reader and the structure follows.