Heading Structure Checker
H1–H6 outline and heading issues
What Is the Heading Structure Checker?
The Heading Structure Checker renders a page and lays out its full H1 to H6 outline, then flags the problems that confuse readers, screen readers and search engines: a missing or duplicate H1, skipped levels, empty headings, repeats and headings that are really paragraphs.
Key Features
Why Heading Structure Matters
Headings are the outline of a page. Screen reader users jump between them to navigate, and search engines use them to understand what each section covers. A clear structure, one H1 then H2s and H3s in order, makes a page easier to scan for people and easier to interpret for machines.
The Mistakes This Catches
Most heading problems come from styling: someone picks an H4 because it looks right, or marks a whole paragraph as a heading to make it bold. Themes and page builders add more, like empty headings around icons. The checker points to each one so you can fix the markup without changing how the page looks.
Common Use Cases
- Checking a page before publishing
- Auditing templates after a redesign
- Fixing accessibility issues flagged in an audit
- Reviewing how a competitor structures a page
Frequently Asked Questions
Is the Heading Structure Checker free?
Yes. It's free with a ProxyHorizon account, and every account gets 25 runs a day shared across all our data tools. You can read about the tool without signing in, but running it needs an account because each run fetches live data.
Is having more than one H1 bad?
It isn't an error in HTML, and Google says it can cope. One clear H1 is still the cleanest structure and the easiest for readers and assistive tech.
What is a skipped heading level?
Jumping from an H2 straight to an H4, for example. It breaks the outline for screen reader users and usually means a heading was chosen for its size.
Does it check JavaScript-rendered headings?
Yes. The page is rendered in a real browser first, so headings added by JavaScript are included.
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