Heading Structure Checker

Check your HTML heading hierarchy for accessibility issues. Find skipped levels, missing H1s, and screen reader problems. Free tool, instant results, no signup.

Paste your HTML and instantly see your heading hierarchy visualised. Find skipped levels, missing H1s, and other issues that confuse screen readers.

  • \u2022Visual tree view shows your exact heading hierarchy at a glance
  • \u2022Detects skipped heading levels (H1 → H3) that break accessibility
  • \u2022Warns about missing or multiple H1 tags
  • \u2022Finds empty headings that screen readers announce incorrectly
  • \u2022Export your heading structure as a clean outline
Tip: Screen readers use headings to navigate. Keep H1 for the main title, then use H2 for sections, H3 for subsections, and so on without skipping levels.

How the Heading Structure Checker Works

  1. 1Paste your HTML code into the input box
  2. 2Click "Check" to analyse the heading structure
  3. 3See a visual tree of all headings with any issues highlighted
  4. 4Fix flagged problems and re-check until you pass

The tool parses your HTML and validates the heading hierarchy against accessibility best practices. Proper heading structure helps screen reader users navigate your content efficiently.

Frequently Asked Questions

Why is heading structure important for accessibility?\u25BC
Screen reader users often navigate pages by jumping between headings. Proper heading structure (H1 → H2 → H3) creates a logical outline they can follow. Skipped levels or missing headings make navigation confusing and content harder to understand.
Should a page have only one H1?\u25BC
Traditionally, yes — one H1 per page representing the main topic. HTML5 technically allows multiple H1s within sectioning elements, but for maximum compatibility with screen readers and SEO, a single H1 is still recommended best practice.
What is a skipped heading level?\u25BC
A skipped heading level occurs when you jump from H1 to H3 (skipping H2) or H2 to H4 (skipping H3). This breaks the logical document outline and confuses screen reader users who expect a hierarchical structure.
How do screen readers use headings?\u25BC
Screen readers let users list all headings on a page and jump directly to any heading. They announce the heading level (e.g., "Heading level 2") so users understand the document structure. This is one of the main ways blind users navigate web content.
Does heading structure affect SEO?\u25BC
Yes. Search engines use heading structure to understand page content and hierarchy. A clear H1 tells Google your main topic. Properly nested H2s and H3s help search engines understand content relationships. Good heading structure benefits both accessibility and SEO.

Why Check Heading Structure?

Proper heading hierarchy is essential for web accessibility. Screen reader users navigate pages by jumping between headings—if your structure skips levels (H1 to H3) or has multiple H1s, users may miss content or become disoriented. Good heading structure also improves SEO by helping search engines understand your content hierarchy.

Common Use Cases

  • Accessibility audits: Verify heading structure meets WCAG 2.1 guidelines before launch
  • SEO optimization: Ensure heading hierarchy helps search engines understand page structure
  • Content review: Check blog posts and articles for proper outline structure
  • CMS migrations: Validate heading structure after importing content from other systems
  • Code review: Quickly audit HTML templates for accessibility issues

Why This Tool?

  • Visual hierarchy: See your heading structure as an indented outline
  • Detailed error messages: Get specific line numbers and fix suggestions
  • 100% client-side: Your HTML never touches our servers
  • Export as outline: Copy heading structure as markdown for documentation

What This Tool Checks

  • Missing H1 - Every page needs one H1 to establish the main topic
  • Multiple H1s - Generally you should have only one H1 per page
  • Skipped Levels - Going from H1 to H3 without H2 confuses screen readers
  • Empty Headings - Headings without text are invisible to assistive technology
  • Heading Order - The first heading should be an H1

Pro tip: Use the "Load Bad Example" button to see common mistakes, then compare with "Load Good Example" to understand proper heading structure.

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