Heading Structure Checker
Check a page's H1–H6 heading outline for missing, duplicate and skipped levels.
About the Heading Structure Checker
See the heading outline of any web page and catch structural problems in seconds. Paste the page’s HTML and the checker lists every H1–H6 tag in order as an indented outline, counts each level, and flags a missing or duplicate H1, skipped heading levels and empty headings.
A logical heading hierarchy helps search engines understand the topics on your page and makes content much easier to navigate for people using screen readers.
How to use the Heading Structure Checker
- 1Open the page in your browser and press Ctrl+U (Cmd+Option+U on Mac) to view its source.
- 2Select all, copy, and paste the HTML into the box.
- 3Review the heading outline and any issues found.
- 4Fix the headings in your CMS or code and check again.
Heading structure best practices
Think of headings as the table of contents for your page:
- Use one H1 that describes the main topic of the page.
- Use H2s for main sections and H3s for sub-sections within them.
- Don’t skip levels — go from H2 to H3, not straight to H4.
- Don’t use headings just to make text big or bold; use CSS for styling.
- Include keywords naturally where they genuinely describe the section.
Frequently asked questions
Do multiple H1 tags hurt SEO?
Google has said multiple H1s won’t cause a penalty, but a single clear H1 is still best practice for clarity and accessibility.
Can I check a live URL instead of pasting HTML?
The tool works on pasted HTML so it can run privately in your browser. For pages that build content with JavaScript, copy the rendered HTML from your browser’s developer tools (Elements panel) instead of the page source.
Why do skipped heading levels matter?
Screen-reader users jump between headings to navigate, and skipped levels make the structure confusing. It also blurs how sections relate to each other.
Is Heading Structure Checker free to use?
Yes — Heading Structure Checker is completely free with no signup, no limits and no hidden costs.
Is my data private and secure?
Everything runs entirely in your browser — your files and text never leave your device, ensuring complete privacy.
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