Schema.org and LLMs

In brief

Schema.org is a standardised vocabulary of structured data, created in 2011 by Google, Microsoft, Yahoo and Yandex. It allows annotating HTML content so that consumers that parse the markup can identify entities, properties and relationships. Whether a particular search or answer product consumes a field is product-specific. This guide covers accurate JSON-LD implementation and the limits of what it proves.

1. What schema.org can and cannot prove

Structured data has two defensible uses:

1. Description. Markup can state that a visible page is an article, identify its author and dates, or describe an organisation and breadcrumbs.
2. Supported Search features. Google documents required and recommended properties for specific rich-result types. Eligibility still does not guarantee display.

Google says no special markup is required for AI Overviews or AI Mode and that structured data must match visible content. OpenAI and Perplexity do not document a general schema.org ranking or citation effect. Validation therefore proves syntax and, for supported Google features, eligibility conditions; it does not prove ranking, citation or model training.

2. Schema types by page type

2.1 Article / BlogPosting

To use on all editorial content pages (articles, guides, analyses). Commonly useful fields, subject to the consumer's current documentation:

{
  "@context": "https://schema.org",
  "@type": "Article",
  "headline": "Exact article title",
  "description": "150-160 character summary",
  "datePublished": "2026-04-22",
  "dateModified": "2026-04-22",
  "inLanguage": "en",
  "author": {
    "@type": "Organization",
    "name": "Your organisation",
    "url": "https://your-site.com"
  },
  "mainEntityOfPage": "https://your-site.com/article/"
}

Common errors: publishing a dateModified that does not match a substantive visible revision, using an empty description, or identifying an author that the page does not show.

2.2 FAQPage

To use on pages containing a questions/answers section. Use this type only when the page visibly contains questions with answers and the applicable consumer still supports the intended feature. Google stopped showing FAQ rich results in May 2026.

{
  "@context": "https://schema.org",
  "@type": "FAQPage",
  "mainEntity": [
    {
      "@type": "Question",
      "name": "What is RAG?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "RAG (Retrieval Augmented Generation) is a system that allows an LLM to consult external sources before generating its response, to produce cited and up-to-date answers."
      }
    }
  ]
}

Quality rule: each answer must match the visible answer. There is no documented 40-word minimum. Write the shortest complete answer the user needs.

2.3 Organization

Use on the homepage or About page when it accurately describes the organisation. It can link your site to your Wikidata, Wikipedia, LinkedIn, Crunchbase profiles via sameAs. Each URL should genuinely identify the same entity.

{
  "@context": "https://schema.org",
  "@type": "Organization",
  "name": "Name of your organisation",
  "url": "https://your-site.com",
  "logo": "https://your-site.com/logo.png",
  "description": "Factual description in 1-2 sentences",
  "foundingDate": "2024",
  "sameAs": [
    "https://www.wikidata.org/wiki/Q...",
    "https://www.linkedin.com/company/...",
    "https://en.wikipedia.org/wiki/..."
  ]
}

2.4 BreadcrumbList

Use where a visible breadcrumb trail represents the page hierarchy. Follow Google's Breadcrumb structured data requirements if Google Search is the target consumer.

{
  "@context": "https://schema.org",
  "@type": "BreadcrumbList",
  "itemListElement": [
    {
      "@type": "ListItem",
      "position": 1,
      "name": "Home",
      "item": "https://your-site.com/"
    },
    {
      "@type": "ListItem",
      "position": 2,
      "name": "Insights",
      "item": "https://your-site.com/insights/"
    },
    {
      "@type": "ListItem",
      "position": 3,
      "name": "Schema.org and LLMs"
    }
  ]
}

2.5 HowTo

HowTo can describe a visible step-by-step procedure, but Google does not document it as an AI Overview citation tactic. Check current Search feature support before investing in markup.

{
  "@context": "https://schema.org",
  "@type": "HowTo",
  "name": "How to optimise your site for LLMs",
  "step": [
    {
      "@type": "HowToStep",
      "position": 1,
      "name": "Step 1: Audit robots.txt",
      "text": "Verify that the major AI bots (GPTBot, PerplexityBot, ClaudeBot) are not blocked in your robots.txt."
    },
    {
      "@type": "HowToStep",
      "position": 2,
      "name": "Step 2: Add Article schema",
      "text": "Add a JSON-LD Article block with datePublished and dateModified on each content page."
    }
  ]
}

2.6 WebSite

WebSite can describe the site's name and URL. Do not promise a sitelinks search box: Google removed that visual element in November 2024.

{
  "@context": "https://schema.org",
  "@type": "WebSite",
  "name": "Site name",
  "url": "https://your-site.com",
  "inLanguage": "en",
  "description": "Short site description"
}

Note: do not duplicate the WebSite schema across multiple pages - one instance on the homepage is sufficient.

3. Injecting multiple schemas on the same page

The recommended technique in 2026 is to inject a JSON-LD array containing multiple schema objects in a single <script type="application/ld+json"> tag:

<script type="application/ld+json">
[
  {
    "@context": "https://schema.org",
    "@type": "Article",
    "headline": "...",
    "datePublished": "2026-04-22",
    "dateModified": "2026-04-22"
  },
  {
    "@context": "https://schema.org",
    "@type": "FAQPage",
    "mainEntity": [...]
  }
]
</script>

JSON-LD arrays and separate script tags can both be valid. Test syntax and the requirements of the specific consumer; do not assume every answer engine parses every object.

4. Schema errors that harm AI visibility

4.1 Schema inconsistent with visible content

If your FAQPage schema lists questions absent from the visible HTML, it violates Google's structured-data guidance. Rule: schema must reflect what a user would see on the page, not invisible or truncated content.

4.2 Incorrect or missing date data

datePublished: "2026" is not a valid ISO 8601 format. Use "2026-04-22" (YYYY-MM-DD) or "2026-04-22T10:00:00+00:00" (with time and timezone). An invalid format is ignored by parsers.

4.3 Organization.sameAs pointing to broken URLs

A broken or incorrect sameAs URL misdescribes the entity. Check that each link resolves and identifies the same organisation or person.

4.4 WebSite schema duplicated across multiple pages

Keep a single consistent WebSite entity, normally rooted on the homepage. Duplicate or conflicting site entities can make the markup harder to interpret.

4.5 Malformed JSON-LD

Invalid JSON (missing comma, unescaped quote, unclosed brace) causes the parser to completely ignore the block. Verify with the Rich Results Test before any deployment.

5. Schema.org and AI surfaces in 2026

6. Action plan: implementation priorities

1. Week 1. Inventory existing markup and map each type to visible content and a documented consumer. Remove false or conflicting properties.
2. Week 2. Add or repair Article markup on editorial pages where dates, headline and author are visible and accurate.
3. Week 3. Add Organization schema on the homepage with sameAs fields completed (Wikidata, LinkedIn or Wikipedia only when they genuinely identify the same entity).
4. Week 4. Add BreadcrumbList where a visible hierarchy exists. Validate syntax and current feature eligibility before deployment.

Structured data checklist

• Article markup is used only on pages that are genuinely articles
• dateModified updated on each substantial revision
• FAQPage is not presented as an AI Overview or rich-result shortcut
• Every marked-up answer matches the visible answer, with no arbitrary word minimum
• Organization schema with sameAs on the homepage
• WebSite schema only on the homepage (not duplicated)
• BreadcrumbList matches the visible page hierarchy
• JSON-LD validated via Rich Results Test before deployment
• Schema/visible content consistency verified

FAQ