RDFa (Resource Description Framework in Attributes) is a W3C standard for adding structured data to a page through extra attributes in the HTML. The data sits next to the visible content it describes.
How does RDFa work?
The W3C describes RDFa as markup attributes that augment the visual information on the web with machine-readable hints. The main attributes are vocab for the default vocabulary, typeof for the type of an item, property for a property, resource and about for the subject or target of a statement, prefix for vocabulary prefixes, and content for a machine-readable value. The current version is RDFa 1.1, whose Third Edition of the Core specification is a W3C Recommendation.
For SEO, RDFa is one of three formats Google supports for structured data, next to JSON-LD and Microdata. Google recommends JSON-LD where the site setup allows it, because it is the easiest to implement and maintain at scale.
| Format | Where does the markup go? | Relation to visible content | Google's position |
|---|---|---|---|
| JSON-LD | in a <script type="application/ in the <head> or <body> | separate from the visible text; nested data is easy to express | recommended as easiest to implement and maintain at scale, less prone to user errors; also read when injected with JavaScript |
| Microdata | as attributes on HTML elements, usually in the <body>, also possible in the <head> | nested within the HTML content | supported; equally fine for Google as long as the markup is valid and implemented per the documentation |
| RDFa (this term) | as attributes on HTML elements, in the <head> and <body> | attributes on elements with user-visible content | supported; equally fine for Google as long as the markup is valid and implemented per the documentation |
All three formats are syntaxes for the same vocabulary: according to schema.org, its types and properties can be expressed in Microdata, RDFa and JSON-LD. Google supports all three unless the documentation for a specific feature says otherwise. Google recommends JSON-LD but calls all three formats equally fine as long as the markup is valid. Sources: Google Search Central: Introduction to structured data markup in Google Search (last updated 2025-12-10); schema.org: Data model. Last checked: .
Example
An organization marked up with RDFa and schema.org:
<div vocab="https://schema.org/" typeof="Organization">
<span property="name">Example Inc.</span>
<a property="url" href="https://www.example.com/">Website</a>
</div>
Sources
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