HTML heading outline checker

Paste a page's HTML to see its heading structure and find accessibility problems such as skipped heading levels.

About this tool

Screen reader users navigate by headings, so levels should not skip (for example h2 straight to h4), and a page normally has one h1. Pasted HTML is read with simple pattern matching in your browser and never sent anywhere, so unusual markup (headings split across templates or generated by scripts) can be missed. This checks heading structure only, not whether headings are well written.