JSONLD

JSON-LD is a lightweight linked data format for expressing structured data in JSON. It is designed to be easy to use for web developers while enabling data to be interlinked across documents and domains. JSON-LD allows resources to be identified with IRIs and described using a flexible, context-driven vocabulary, making it possible to merge data from diverse sources without loss of meaning.

A core concept is the @context, which maps terms used in the document to IRIs, vocabularies, or terms defined by the user. This context lets simple property names like name or date be expanded to globally unique identifiers. The @id field provides a unique IRI for a node, while @type assigns an RDF class or concept. Literal values can be represented with @value, optionally accompanied by @language for language-tagged strings or @type for typed literals. JSON-LD also supports structured constructs such as @graph for describing multiple nodes and @list or @set for collection-like data.

JSON-LD defines a processing model that includes expansion, compaction, framing, and flattening. Expanded form resolves terms to full IRIs, while compacted form re-maps them to short terms suitable for humans. JSON-LD data can be transformed into RDF triples, enabling interoperable data exchange with traditional semantic web technologies. Tools and libraries exist in many programming languages to parse, serialize, and convert JSON-LD, and processors can integrate with standards such as RDF and OWL.

JSON-LD became a W3C Recommendation in 2014, with a 1.1 revision published in 2020. It is widely used for embedding structured data on the Web, notably with schema.org vocabularies, to improve discoverability and interoperability across applications and datasets.