RDFa
RDFa (Resource Description Framework in Attributes) is a W3C specification for embedding RDF-based structured data directly inside the attributes of a host markup language, most commonly HTML, XHTML, SVG, or arbitrary XML. Rather than being a standalone file format, RDFa is an in-document annotation layer: the same markup that renders a page for humans also carries machine-readable statements, avoiding the duplication that a separate metadata file would require. It was first proposed by Mark Birbeck in 2004 as the note "XHTML and RDF" and matured through the W3C, with RDFa 1.0 reaching Recommendation in 2008 and RDFa Core 1.1 in 2012 (revised 2015); editors included Ben Adida, Mark Birbeck, Shane McCarron, and Ivan Herman.
The data model is exactly RDF: a processor walks the document tree depth-first and emits subject-predicate-object triples, so RDFa is a serialization of the same graph model expressed by Turtle, RDF/XML, N-Triples, and JSON-LD. Meaning is carried by a fixed set of attributes: @about names a subject, @property and @content assert literal-valued predicates, @rel/@rev and @resource/@href/@src assert resource-valued relationships, @typeof assigns rdf:type, and @datatype and @lang/xml:lang qualify literals. Namespaces are handled with @prefix (RDFa 1.1 dropped the earlier reliance on XML namespaces) and @vocab sets a default vocabulary so bare terms resolve to full IRIs. RDFa Lite is a deliberately minimal subset—vocab, typeof, property, resource, prefix—aimed at authors who want schema.org markup without the full machinery.
In practice RDFa's largest deployments are search-engine and social metadata: schema.org vocabularies for rich results, and Facebook's Open Graph protocol, which is defined as an RDFa vocabulary. Datasets such as DBpedia and semantic-publishing pipelines also consume it. Because output is standard RDF, extraction tools built on Jena/RIOT, RDFLib (Python), or EasyRdf Converter can lift the triples into a triplestore or convert them to any other RDF syntax.
Its strengths are full RDF expressiveness inside human-readable pages, vocabulary independence, and no data duplication. Limitations are real: the attribute model has subtle scoping and chaining rules that are error-prone to author by hand, and since roughly 2013 adoption for new work has shifted toward the simpler, non-intrusive JSON-LD, which many publishers and Google now favor over inline attribute markup.
Alternative Names: Resource Description Framework in Attributes, RDFa Core
SpecificationTools(Read & Write)
Frequently Asked Questions
What is a RDFa (Resource Description Framework in Attributes) file?
A RDFa (Resource Description Framework in Attributes) file stores a graph — its nodes, edges and attributes — in the RDFa (Resource Description Framework in Attributes) format (also: Resource Description Framework in Attributes, RDFa Core). See the feature table above for what it supports.
How do I open a RDFa (Resource Description Framework in Attributes) file?
Open it in a graph tool that supports RDFa (Resource Description Framework in Attributes), or convert it to a format your tool reads. With GraphInOut you can convert RDFa (Resource Description Framework in Attributes) to GraphML, DOT, Connected JSON and more, right in your browser.
How do I convert a RDFa (Resource Description Framework in Attributes) file to another format?
Use the Convert from RDFa (Resource Description Framework in Attributes) link above: upload or paste your RDFa (Resource Description Framework in Attributes) file (input preset to RDFa (Resource Description Framework in Attributes)), choose a target format and download the result — free, no install.