Structured Data
JSON-LD
The recommended syntax for embedding Schema.org structured data on a page. Lightweight, decoupled from page HTML, and increasingly the format LLMs prefer when retrieving structured facts.
What it is
JSON-LD is a JSON-based serialisation for embedding Schema.org structured data, placed in a script block rather than woven into visible HTML. It expresses entities and their relationships as linked data that machines can parse independently of page layout.
Why it matters
Its separation from the rendered DOM makes facts easier and cheaper for crawlers and LLMs to extract reliably, and it is the format generative systems increasingly favour when retrieving structured facts.
How it works
You declare a context and type, then list properties as key value pairs, often linking nodes by @id so that entities reference one another across the same page or site.
When it applies
It applies to any page where you want structured facts represented cleanly and decoupled from presentation markup.
Examples
- A script type application ld plus json block in the head describing an Organisation
- Linking an Article node to its author Person node via a shared @id
- A FAQPage block listing question and answer pairs as structured nodes
How it is measured
- JSON-LD parses as valid JSON and as valid linked data
- Entities correctly cross-reference via @id without dangling references
- Consistency between JSON-LD claims and the visible on-page content
- Share of structured data delivered as JSON-LD versus microdata or RDFa
Related terms in Structured Data
- Knowledge graph entityA node in Google's Knowledge Graph representing a real-world thing (person, place, organisation, work). Strong entity signals are prerequisite for Search Profile eligibility and consistent AI Overview attribution.
- Retrieval-augmented generationA generation approach where an LLM pulls relevant documents at query time and uses them as the source for its answer. The pattern behind most enterprise AI search products and Perplexity-style answer engines.
- Schema.orgThe shared vocabulary for structured-data markup used by Google, Microsoft, and major search engines. As of June 2026, Schema.org publishes monthly aggregate adoption statistics by type.
- Structured dataMarkup (typically JSON-LD using Schema.org vocabulary) that tells search engines and LLMs what the entities and relationships on a page are. Increasingly important as both Google and generative systems converge on entity-level understanding.