Heading Checker
Audit your H1โH6 structure.
Heading Checker at a glance
Heading Checker is a free online seo tool you can use right now to audit your H1โH6 structure โ no account, no install and no usage limit. It runs entirely inside your browser, so whatever you enter stays on your own device.
- Price
- Free โ no trial, no paid tier, no watermark
- Sign-up
- Not required
- Where it runs
- In your browser โ nothing is uploaded to a server
- Works on
- Chrome, Safari, Firefox and Edge โ desktop, tablet and phone
- Category
- SEO Tools
About Heading Checker
Extract a page's heading structure and see its outline, with skipped levels and missing or duplicated H1s flagged.
Headings are the document's table of contents, and both search engines and screen readers rely on them for exactly that. Screen reader users navigate by jumping between headings rather than reading linearly โ it is one of the most-used navigation methods โ so a broken hierarchy is a genuine accessibility problem, not only an SEO nicety.
The rule is that levels descend without gaps: an H1 for the page's subject, H2s for major sections, H3s nested under those. Jumping from H2 straight to H4 leaves a hole in the outline, and a screen reader user hears that a level is missing without knowing what belongs there.
The most common cause of a broken hierarchy is choosing heading levels for their size. An H4 gets used because the design calls for smaller text, which breaks the structure for a purely visual reason. Choose the level that reflects the content's place in the hierarchy and set the size in CSS. Similarly, one H1 per page is the sensible convention โ modern HTML technically permits more within sectioning elements, but a single H1 stating the page's subject remains clearest for everyone.
How to use Heading Checker
- Paste your page's HTML or enter its URL.
- Review the extracted outline from H1 through H6.
- Fix any skipped levels, missing H1 or duplicate top-level headings.
Frequently asked questions
Should a page have exactly one H1?
One is the sensible convention โ it states what the page is about. Modern HTML permits multiple H1s inside sectioning elements, but a single H1 remains clearest for search engines and screen reader users alike.
Why does skipping a heading level matter?
Screen reader users navigate by jumping between headings, so a gap in the sequence leaves them with a structure that does not make sense. It also weakens the outline search engines build from your page.
Can I use a heading purely because I want smaller text?
No โ that is the most common cause of broken hierarchies. Pick the level that matches the content's position in the outline and control size with CSS.
Do headings still matter for SEO?
Yes, though less as a direct ranking factor than as structure. They tell search engines how a page is organised and which passages answer which questions, which matters increasingly for passage-level ranking and AI-generated answers.