# Heading hierarchy

> Heading hierarchy is the order of headings from H1 to H6. A correct outline nests them by level without skipping any, like the chapters and sections of a book.

- **Check ID:** S4
- **Area:** [SEO](https://be1st.ai/glossary/seo)
- **Tool:** [SEO + Security + Performance](https://be1st.ai/tools/ssp-audit)
- **Page:** https://be1st.ai/glossary/seo/heading-hierarchy

## Why it matters

Proper heading hierarchy helps search engines understand the structure and relationships between content sections. It also improves accessibility for screen readers and the overall usability of the page.

## In practice

MDN Web Docs uses flawless heading hierarchy on every documentation page. Conversely, pages that jump from H1 to H4 lose semantic context and search engines cannot properly interpret the content structure.

## How be1st checks it

Checks for proper heading hierarchy from H1 through H6 without skipping levels. Correct hierarchy means H1 -> H2 -> H3 without jumping levels (e.g., going from H1 directly to H3). The check reports every skip, not just the first one.

[SEO + Security + Performance](https://be1st.ai/tools/ssp-audit), SEO tab.

Every check ends as: Pass, Warning, Fail.

## Sources

- [SEO Starter Guide](https://developers.google.com/search/docs/fundamentals/seo-starter-guide) (Google Search Central)
- [Lighthouse SEO Audits](https://web.dev/articles/pass-lighthouse-seo-audit) (web.dev)

## Related terms

- [Content structure (lists, tables)](https://be1st.ai/glossary/ai-readiness/content-structure): Content structure is how a page organizes information into lists, tables and other formats that readers and AI models can scan quickly.
- [Canonical URL](https://be1st.ai/glossary/seo/canonical-url): A canonical URL is the preferred address of a page, set with `<link rel='canonical'>`. It tells search engines which version to index when the same content has several URLs.
- [Viewport meta tag](https://be1st.ai/glossary/seo/viewport-meta-tag): The viewport meta tag tells mobile browsers how wide to lay out a page and how to scale it. Without it, a phone shows a shrunken desktop page.
- [Robots meta tag](https://be1st.ai/glossary/seo/robots-meta-tag): The robots meta tag gives search engines instructions for one page, such as noindex (keep it out of results) or nofollow (do not follow its links).
- [Open Graph tags](https://be1st.ai/glossary/seo/open-graph-tags): Open Graph tags are meta tags with the og: prefix that set the title, description and image a page shows when it is shared on Facebook, LinkedIn, Slack and other apps.
- [Twitter Card tags](https://be1st.ai/glossary/seo/twitter-card-tags): Twitter Card tags are meta tags with the twitter: prefix that control how a link preview looks when a page is shared on X, formerly Twitter.