What is sameAs in structured data

Full definition

sameAs is a property in the Schema.org vocabulary. Its value is one or more URLs, each pointing to an external page that unambiguously identifies the same entity — person, organisation, product, or place — described on the current page. The property originates in the Linked Data and RDF tradition, where owl:sameAs has been used since the mid-2000s to declare entity equivalence across datasets.

In practice, for a UK trade business the sameAs array typically contains: the Google Business Profile URL, the Wikidata entity URL (if one exists), the LinkedIn company page, the Companies House entry, and any regulated-body registrations (for example, a Gas Safe Register public profile for heating engineers).

The property is placed inside the main JSON-LD block for the page entity — most commonly inside the LocalBusiness or Organization object:

"sameAs": [
  "https://www.google.com/maps/place/?q=place_id:ChIJExample",
  "https://www.wikidata.org/wiki/Q12345678",
  "https://www.linkedin.com/",
  "https://find-and-update.company-information.service.gov.uk/company/12345678"
]

Each URL must be publicly accessible and must clearly refer to the same business. Broken, redirected, or mismatched URLs can weaken rather than strengthen entity confidence.

Why it matters in 2026

Knowledge Graphs — the internal databases that power Google's Knowledge Panel, Bing's entity answers, and the entity-resolution layers inside ChatGPT and Perplexity — are built by merging signals from multiple sources. sameAs is the explicit bridge that tells a crawler: these pages describe one entity, not separate ones.

Without sameAs, the same business may be represented as multiple partial nodes in a Knowledge Graph: one from the website, one from a directory listing, one from a social profile. None accumulates enough confidence to surface in AI-generated answers or trigger a Knowledge Panel. With a correct sameAs chain, all authority signals from every linked source consolidate onto one node, raising the entity's prominence score.

For tradesmen operating in competitive local markets — plumbers, electricians, roofers — where dozens of businesses share generic names, a sameAs link to a unique company registration number or regulated-body profile is often the tie-breaker that enables reliable entity matching.

How it works

Entity resolution engines follow a three-step process when they encounter sameAs:

1. Crawl and cache the current page's JSON-LD, noting the entity and its claimed equivalences.
2. Crawl each listed sameAs URL and verify consistency of name, address, and other key properties.
3. Merge all consistent sources into a single entity node, accumulating ratings, mentions, and citations from all of them.

The confidence threshold for merging varies by engine, but a sameAs chain that passes name-address consistency checks at three or more authoritative sources — Google Business Profile, Wikidata, national company register — typically crosses the threshold for Knowledge Panel generation.

Difference from a standard hyperlink

Attribute	sameAs property	Ordinary hyperlink
Semantic meaning	"This URL describes the same entity"	"This URL is related or cited"
Effect on Knowledge Graph	Triggers entity merge	No entity-resolution effect
Location	JSON-LD structured data	Visible HTML anchor tag
Crawl priority	High (structured-data pass)	Normal (link graph pass)
Directionality	Bidirectional equivalence claim	Unidirectional reference

Related terms

LocalBusiness schema, JSON-LD, E-E-A-T.