Heading Structure Checker

Heading Structure Checker (H1–H6) is a lightweight Chrome extension designed to help website owners, SEO specialists, content editors, and developers quickly review the structural quality of HTML headings.

The extension allows you to paste raw HTML content and instantly analyze the hierarchy of heading tags from H1 to H6. It generates a clear outline, displays heading counts, and highlights common structural issues such as missing H1 tags, multiple H1s, skipped heading levels, or improperly ordered headings.

All analysis is performed locally inside the browser using standard web APIs. The extension does not access web pages, does not collect data, and does not require any special permissions. Your content is never transmitted or stored externally.

Key features include:

Paste-based HTML analysis with no page access

Automatic detection of H1–H6 heading structure

Visual heading outline for quick review

Summary statistics for each heading level

Warnings for common hierarchy mistakes

Clean, professional user interface

Works fully offline with zero permissions

This tool is ideal for improving content accessibility, SEO structure, and document clarity before publishing HTML content.