Why does heading structure matter for accessibility?

Screen readers use headings to let users navigate content quickly. A logical hierarchy (H1 > H2 > H3) ensures users can jump between sections without confusion, meeting WCAG 2.1 Success Criterion 1.3.1 (Info and Relationships).

Is it valid to have more than one H1 on a page?

HTML5 technically allows multiple H1s in sectioning elements, but best practice for SEO and screen reader compatibility is to have exactly one H1 per page that describes the main topic.

What counts as a skipped heading level?

A skipped level means jumping from a higher level to a non-consecutive lower level — for example, H1 directly followed by H3 without an H2 in between. This breaks the logical outline and confuses assistive technology users.

Does this tool send my HTML to a server?

No. All analysis runs entirely in your browser using JavaScript. Your content is never transmitted to any server.

Can I analyze plain text without HTML tags?

Yes. If no heading tags are detected, the tool treats lines starting with "#" (Markdown) or all-caps short lines as potential headings and notes they could be tagged properly.

Heading Structure Helper

Name: Heading Structure Helper
Availability: InStock
Author: Nham Vu

Paste HTML or plain text and instantly see a visual map of your heading hierarchy with accessibility and SEO issue warnings.

Paste HTML or Text

Paste your full HTML source, a snippet, or plain text below.

Paste your HTML or text on the left and click Analyze Headings.

Summary

Paste HTML or plain text and instantly see a visual map of your heading hierarchy with accessibility and SEO issue warnings.

How it works

Paste your HTML source or plain text into the input box.
Click "Analyze Headings" to parse heading tags (H1–H6).
A visual tree shows each heading indented by its level.
Issue badges flag missing H1, skipped heading levels, or multiple H1s.
Fix any flagged issues and re-analyze to confirm compliance.

Use cases

Audit blog posts or landing pages for proper heading hierarchy.
Check CMS-generated content for heading accessibility compliance.
Verify documents meet WCAG 2.1 heading order requirements.
Debug SEO issues caused by missing or duplicate H1 tags.
Review student or client HTML submissions for structure correctness.
Ensure heading levels are not skipped (e.g., H1 jumping to H3).

Frequently Asked Questions

Last updated: 2026-07-01 · Reviewed by Nham Vu