Developer Tools

Heading Hierarchy Validator — Free, No Upload, Browser-Based

🔒 Werkt in je browser

Paste HTML or Markdown and instantly see a visual outline of your h1–h6 heading hierarchy, with plain-English issue reports for skipped levels and multiple h1 tags. Good heading structure matters for both screen-reader accessibility and SEO — this tool catches the most common mistakes before they ship. Everything runs in your browser: no upload, no account, and your markup is never sent anywhere.

Hoe gebruik je deze tool

  1. Selecteer HTML of Markdown als invoerformaat en plak je inhoud in het tekstgebied.
  2. Het gereedschap parseert elke h1–h6-kop en controleert op overgeslagen niveaus of meerdere h1-tags.
  3. Bekijk de visuele omtrek en herstel eventuele gemarkeerde problemen in je bronbestand voordat je publiceert.
Input format

1 issue found

  • line 6h4 follows h2 — skips level h3.

Outline (6 headings)

  • h1Page Title:1
  • h2Section A:2
  • h3Subsection A1:3
  • h4Detail:4
  • h2Section B:5
  • h4Skipped h3!:6
h1×1h2×2h3×1h4×2
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Heading Hierarchy Validator — Free, No Upload, Browser-Based | brevio