Free Tool

Heading Checker

Q: What is WCAG 1.3.1 Info and Relationships?

WCAG Success Criterion 1.3.1 requires that information, structure, and relationships conveyed visually are also available programmatically. For headings, this means using the correct H1-H6 tags instead of styled paragraphs or divs. A heading that looks big but uses a span tag fails this criterion.

A heading checker validates the H1-H6 heading hierarchy on any URL and shows the complete document outline as an indented tree view. OverlayQA's free heading checker extracts all heading tags, flags skipped levels, missing H1 tags, multiple H1s, and empty headings that break accessibility and SEO. No account required.

What Is a Heading Hierarchy?

HTML provides six heading levels: H1 through H6. Together they create an outline of a page's content. Screen readers let users jump between headings to navigate long pages. When the hierarchy is correct (H1 followed by H2, then H3 for subsections), users can scan efficiently. When levels are skipped, the outline breaks. Search engines also use heading structure to determine topical relevance.

How to Check Heading Structure

Enter your URL. Paste any publicly accessible URL into the input field.
Click Check Headings. The tool fetches the page's HTML and extracts all heading tags.
Review the heading tree. See the full hierarchy as an indented tree with level indicators.
Fix reported issues. Address missing H1, skipped levels, and empty headings. Re-check to verify.

Common Heading Mistakes

Missing H1. Every page needs exactly one H1 that describes the primary topic.
Multiple H1 tags. Using more than one H1 dilutes the page's primary topic signal.
Skipped levels. Going from H2 directly to H4 breaks the document outline for screen reader users.
Headings for styling only. Choosing H3 because it looks the right size instead of using CSS is a common mistake.
Empty headings. A heading tag with no text creates a confusing empty landmark.
Non-descriptive headings. Generic headings like "Section 1" or "Read More" provide no context.

Heading Levels Reference

Tag	Purpose	Typical use
H1	Page title	One per page. The primary topic.
H2	Major sections	Blog post sections, feature groups, FAQ headings.
H3	Subsections of H2	Individual features, sub-topics within a section.
H4	Subsections of H3	Detailed breakdowns, nested sub-topics.
H5-H6	Rarely needed	Deep nesting. Consider restructuring if you need these.

Frequently Asked Questions

Is this heading checker free? Yes. Paste any URL and check as many pages as you need. No account, no login, no usage limits.

Why does heading order matter? Screen readers let users navigate pages by jumping between headings. A correct hierarchy creates a clear outline. Skipped levels break that navigation. Search engines also use headings to understand page structure.

How many H1 tags should a page have? One. The HTML spec allows multiple H1 tags inside sectioning elements, but a single H1 per page works best for accessibility and SEO.

Does this tool check WCAG compliance? It checks heading-specific WCAG criteria: proper hierarchy (1.3.1 Info and Relationships), meaningful structure (2.4.6 Headings and Labels), and non-empty headings. For a full WCAG audit, use the OverlayQA accessibility checker.

Can I test localhost or staging URLs? Staging URLs work if they are publicly accessible. Localhost URLs will not work. For local testing, use your browser's developer tools.

What is WCAG 1.3.1 Info and Relationships? This criterion requires that structure conveyed visually is also available programmatically. For headings, use correct H1-H6 tags instead of styled paragraphs or divs.

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Last updated June 2026