Definition

Structured data

What Structured data means

Structured data is machine-readable markup embedded in a page that states what the page is about in a fixed format, instead of leaving that to be inferred from the prose. Google describes it as "a standardized format for providing information about a page and classifying the page content."

More precisely

On the web it is carried in one of three encodings, JSON-LD, Microdata or RDFa, and it usually draws its types and properties from the schema.org vocabulary. Google recommends JSON-LD and can read it when injected by JavaScript. Correct markup makes a page eligible for rich results; eligibility is not a promise that any given result appears.

Why it matters

Google states that there is no special schema.org structured data needed for its AI features, and that structured data is still worth keeping as part of ordinary SEO because it supports rich result eligibility. Those are two separate claims and collapsing them is the usual error.

Example

A recipe page can state its ingredients, cooking time and calorie count in markup rather than leaving a parser to guess them from the layout.

Where this came from

Definitions here follow the specification or documentation that defines the term, not a paraphrase of another glossary.