# Semantic HTML (article, section, nav, aside)

> Semantic HTML uses elements that say what their content is, such as article, section, nav, aside and main, instead of generic div boxes.

- **Check ID:** A20
- **Area:** [AI Readiness](https://be1st.ai/glossary/ai-readiness)
- **Tool:** [AI Readiness](https://be1st.ai/tools/ai-readiness)
- **Page:** https://be1st.ai/glossary/ai-readiness/semantic-html

## Why it matters

AI crawlers use semantic HTML elements to identify the main content of a page. The article element marks primary content, nav marks navigation, and aside marks secondary content: this helps AI ignore noise and extract relevant content.

## In practice

Web.dev (Google) consistently uses semantic HTML: main content is in article, navigation in nav, and related links in aside. AI crawlers can thus efficiently extract only the educational content without navigational noise.

## How be1st checks it

Checks the use of semantic HTML5 elements: article, section, nav, aside, main, figure and figcaption. Three or more different elements mean the check passes. These elements provide AI models with contextual information about the role of each part of the page.

[AI Readiness](https://be1st.ai/tools/ai-readiness), Technical tab.

Every check ends as: Pass, Warning, Fail.

## Sources

- [Google Search Essentials](https://developers.google.com/search/docs/essentials) (Google)

## Related terms

- [Markdown for AI agents](https://be1st.ai/glossary/ai-readiness/markdown-for-ai-agents): Markdown for AI agents means a website can serve a page as clean Markdown, through a .md URL or content negotiation, instead of the full HTML.
- [Dashes in text (AI writing tell)](https://be1st.ai/glossary/ai-readiness/dashes-in-text): Long dashes in a text (the em dash, and the en dash outside number ranges) are the best known trace of text written by a language model.
- [Organization schema](https://be1st.ai/glossary/ai-readiness/organization-schema): Organization schema is Schema.org structured data that describes the company behind a website: its name, logo, contact details and social profiles.
- [Product schema](https://be1st.ai/glossary/ai-readiness/product-schema): Product schema is Schema.org structured data that describes a product or service: its name, price, availability and reviews.
- [FAQ schema](https://be1st.ai/glossary/ai-readiness/faq-schema): FAQ schema is Schema.org structured data (FAQPage) that marks up the questions and answers on a page in a machine-readable form.
- [Review / rating schema](https://be1st.ai/glossary/ai-readiness/review-rating-schema): Review and AggregateRating schema are Schema.org structured data that describe the reviews and the average rating of a product or service.