# Semantic HTML: structure for readers and parsers

German title: Semantisches HTML: Struktur für Leser und Parser

> Semantic elements such as article, section, header, nav and a clear heading hierarchy make pages more readable for people and machines. That RAG systems cut at headings or that semantic HTML brings higher retrieval quality is not verified. Google flattens shadow DOM content and uses headings for title links.

## Facts

- **Title link:** uses headings among other sources
- **Shadow DOM:** flattened by Google

## Verified

- Google includes heading elements and the visible main heading when forming title links.
- Google flattens content from shadow and light DOM; important content must appear in the rendered HTML.
- Key statements should be in the delivered HTML, not only in canvas or later-loaded JavaScript (see the report on JavaScript and crawlers).

## Rules of this website (recommendation)

- One H1 per page; H2 for sections, H3 for details.
- Tables and lists as their own elements, not as images.
- Short paragraphs with one statement.

ARIA roles complement native semantics but do not replace them; no source was read on this.

## Not verified

This report describes a working model of the author. There is no primary source from Google, OpenAI, Perplexity or Anthropic for the individual steps; read them as recommendations, not as verified effects.

## Sources

- Google Search Central: Influencing your title links (primary source)
- Google Search Central: JavaScript SEO basics (primary source)

Checked on: 24 October 2026.

## Questions

### How long may a section be?

There is no verified value.

### Are ARIA roles enough?

No source was read on this. Native elements are the simpler choice.

### Does semantic HTML improve RAG chunking?

That is not verified.

## Related

- [JavaScript and crawlers: content in the first HTML](https://munichmedia.com/reports/aeo-crawler-javascript.md)
- [Schema.org for AEO: what is verified](https://munichmedia.com/reports/aeo-schema-org-basis.md)
- [Direct answers for answer engines](https://munichmedia.com/reports/direktantworten-answer-engines.md)
- [Headless CMS: quality checks in the build](https://munichmedia.com/reports/aeo-headless-cms-pipeline.md)

Canonical HTML: https://munichmedia.com/reports/aeo-dom-semantic-html