Accessibility

Heading Structure Visualizer

Paste HTML to see its H1–H6 outline as a tree and catch structural problems such as skipped levels, empty headings, and missing or duplicate H1s. Everything runs in your browser — your markup never leaves the page.

Runs in your browser v1.0.0

HTML source

inert parser

Paste a full page or a fragment. Script, style, and template contents are ignored, and pasted code is never executed.

Heading outline

live

Issues

errors and warnings

How it works

The HTML is scanned in an inert, string-based parser: comments and the contents of script, style, template, and similar elements are ignored, so the outline reflects real visible headings. Headings are nested by level, then checked for common accessibility problems. Nothing is sent to a server and no code from your markup is run.