Search basics
Structured data
Code that describes a page's content in the schema.org vocabulary, so search engines can read facts such as the author, price or rating directly. Google recommends the JSON-LD format.
Also called schema markup, JSON-LD, schema.org · Sources checked 15 November 2026
Google accepts three formats, JSON-LD, Microdata and RDFa, and says all three are equally fine if the markup is valid. It marks JSON-LD as the recommended one; it sits in a single script block, apart from the visible HTML, which makes it the easiest to keep correct.
Two rules from Google's guidelines catch most mistakes. The markup has to describe what readers can see on the page: a review in the markup needs a review in the text. And valid markup makes a page eligible for a rich result, such as review stars, without guaranteeing one.