Schema.org is a shared vocabulary for describing the content of a web page to machines. Google, Microsoft, Yahoo, and Yandex created it, and it is developed in an open community process through the W3C mailing list and GitHub. “Schema markup” means annotating a page with this vocabulary.
How is schema.org structured?
The vocabulary consists of types and properties. A type says what something is, such as Product, Person, Event, or Organization. Properties describe it, for example name, price, or startDate. The most general type is Thing, which has the properties name, description, url, and image. More specific types inherit from it, so Place is a kind of Thing and adds its own properties.
Schema.org defines what is described. The syntax comes from a format such as JSON-LD, Microdata, or RDFa. The terms are therefore not interchangeable: schema.org is the vocabulary, JSON-LD is one way to write it down. Google accepts all three formats and recommends JSON-LD.
| Format | Where does the markup go? | Relation to visible content | Google's position |
|---|---|---|---|
| JSON-LD | in a <script type="application/ in the <head> or <body> | separate from the visible text; nested data is easy to express | recommended as easiest to implement and maintain at scale, less prone to user errors; also read when injected with JavaScript |
| Microdata | as attributes on HTML elements, usually in the <body>, also possible in the <head> | nested within the HTML content | supported; equally fine for Google as long as the markup is valid and implemented per the documentation |
| RDFa | as attributes on HTML elements, in the <head> and <body> | attributes on elements with user-visible content | supported; equally fine for Google as long as the markup is valid and implemented per the documentation |
All three formats are syntaxes for the same vocabulary: according to schema.org, its types and properties can be expressed in Microdata, RDFa and JSON-LD. Google supports all three unless the documentation for a specific feature says otherwise. Google recommends JSON-LD but calls all three formats equally fine as long as the markup is valid. Sources: Google Search Central: Introduction to structured data markup in Google Search (last updated 2025-12-10); schema.org: Data model. Last checked: .
What does it mean for SEO?
The markup gives search engines explicit statements, such as which number is a price. Whether Google turns it into a rich result depends on whether Google supports the type and whether the required properties are filled. Google also says markup must match the visible content and must not sit on blank pages. Markup can be checked with the Schema Markup Validator and the Rich Results Test.
Example
<script type="application/ld+json">
{
"@context": "https://schema.org",
"@type": "Event",
"name": "SEO Meetup",
"startDate": "2026-11-12T19:00",
"location": { "@type": "Place", "name": "Example Cafe" }
}
</script>
Common mistakes
- Markup that does not match the visible content. Google asks for markup of content that visitors can see on the page.
- Missing required properties. For rich results, all properties named in the documentation of the result type must be present.
- A type that is too general. Google advises using the most specific applicable schema.org type and property names.
- Typos in type or property names. The Schema Markup Validator reports names that do not exist in the vocabulary.
FAQ
How do I check my schema.org markup? The Schema Markup Validator at validator.schema.org checks syntax and vocabulary. The Rich Results Test checks eligibility for Google features.
What is schema markup? Structured data on a page that uses the schema.org vocabulary, most often written as JSON-LD.
Sources
- Schema.orgschema.org
- Getting started with schema.org using Microdataschema.org
- Introduction to structured data markup - Google Search Centraldevelopers.google.com
- Structured data features gallery – Google Search Centraldevelopers.google.com
- General structured data guidelines – Google Search Centraldevelopers.google.com
Last updated: