What is schema markup?

How schema markup works

Google calls schema markup structured data and defines it as "a standardized format for providing information about a page and classifying the page content." The labels come from schema.org, a shared vocabulary of types such as Article, LocalBusiness and Product.

Google supports three formats and recommends JSON-LD if your site's setup allows it. JSON-LD is a block of code in the page that search engines read and visitors do not see.

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Article",
  "headline": "How often should you clean your gutters?",
  "author": {
    "@type": "Person",
    "name": "Jane Doe",
    "url": "https://example.com/about/jane-doe/"
  },
  "datePublished": "2026-03-10",
  "dateModified": "2026-10-02"
}
</script>

Why Google cares

Google says it uses structured data that it finds on the web to understand the content of the page, and that adding it can enable rich results: search listings with extra details beyond the title and description.

Google is also clear about the limits. Its structured data guidelines state: "Google does not guarantee that your structured data will show up in search results." For AI answers, Google's guide to generative AI features says: "Structured data isn't required for generative AI search, and there's no special schema.org markup you need to add." The same guide advises you to keep using it as part of your overall SEO strategy, because it helps with being eligible for rich results.

What it means for your business

Schema markup is worth the most on pages built around specific facts, such as products, events and articles. Treat it as one part of SEO, after the content of the page and its place in Google's index.

The markup has to match the page: Google's guidelines say not to mark up content that is not visible to readers of the page. We add and check schema as part of our technical SEO services.

Common mistakes

• Marking up content visitors cannot see, such as reviews that do not appear on the page. Google's guidelines rule it out, along with fake reviews; mark up only what the page shows.
• Expecting schema to earn rich results or AI citations on its own. Google does not guarantee rich results, and its AI features guide says no special markup is needed for generative AI search.
• Letting the markup drift from the page, such as an old price or a past event date. Update the schema whenever the page changes.
• Skipping validation. Google points to its Rich Results Test for checking structured data.

Related terms

Sources: Google Search Central, Intro to how structured data markup works, 10 December 2025; Google Search Central, General structured data guidelines, 10 July 2026; Google Search Central, Google's guide to optimizing for generative AI features on Google Search, 10 July 2026.