sameAs

What sameAs means

schema.org defines sameAs as the URL of a reference web page that unambiguously indicates the item's identity, giving as examples the item's Wikipedia page, Wikidata entry or official website. For a person, that means pages that are about this person and nobody else: the person's own account on a platform, their ORCID record, their Wikidata item.

schema.org's sameAs is looser than owl:sameAs in the Web Ontology Language, which states that two identifiers denote the very same thing. In schema.org, the value is a page that identifies the person, not a second identifier for the person. Consumers still treat a sameAs link as strong evidence that the two records belong together, which is why a wrong value does real damage.

An example

{
  "@context": "https://schema.org",
  "@type": "Person",
  "@id": "https://lenamarlowe.example/#person",
  "name": "Lena Marlowe",
  "url": "https://lenamarlowe.example/",
  "sameAs": [
    "https://www.linkedin.com/in/lena-marlowe-example",
    "https://github.com/lena-marlowe-example",
    "https://orcid.org/0000-0002-1825-0097",
    "https://www.wikidata.org/wiki/Q00000000"
  ]
}

The Wikidata value is a placeholder: only link an item that is about this exact person.

What belongs in sameAs

• The person's own accounts: profiles on LinkedIn, GitHub, X, Mastodon, YouTube and similar sites that the person controls.
• Registry records: the ORCID record, the ISNI or VIAF page, a Library of Congress name authority. These pages identify the person by definition.
• Knowledge base entries: the Wikidata item, or a Wikipedia article about the person.

Common mistakes

• A namesake's account. The most damaging error: it tells every consumer that two people are one. Link only accounts proven to be the person's.
• Pages that mention the person. A news article or a team page is about something else; use subjectOf for pages about the person, and worksFor for the employer.
• The page itself, or its own site. The person's own website belongs in url; the page you are on is already the context.
• Search or listing URLs. https://www.linkedin.com/search/results/people/?keywords=... identifies nothing.
• Unstable addresses. Tracking parameters, mobile subdomains and redirects make the same account look like several. Use the canonical profile URL.
• One string instead of a list. Several values go in a JSON array, not in one comma-separated string.

Two-way links and rel="me"

A sameAs link is a claim made by one page. It is much stronger when the other page confirms it: the person's website links to their GitHub profile, and the GitHub profile links back to the website. In HTML, rel="me" on a link states that the linked page represents the same person as the current one; Mastodon and other IndieWeb tools use it to show a profile link as verified.

<!-- On https://lenamarlowe.example/ -->
<a href="https://github.com/lena-marlowe-example" rel="me">GitHub</a>

<!-- And the GitHub profile's website field points back to https://lenamarlowe.example/ -->

How SelfBadge fills sameAs

On a SelfBadge profile, sameAs holds only accounts the owner added or proved: connected through the platform's own sign-in, or confirmed by a link back. Registry identifiers with a page (ORCID, ISNI, Wikidata) are listed both as identifier and, by URL, in sameAs. Accounts found in public sources for profiles that nobody has claimed are not published in sameAs until the person claims the profile. See Verification levels.