Canonical link element
type of hyperlink
A canonical link element is an HTML element that helps webmasters prevent duplicate content issues in search engine optimization by specifying the "canonical" or "preferred" version of a web page. It is described in RFC 6596, which went live in April 2012.
Purpose
A major problem for search engines is to determine the original source for documents that are available on multiple URLs. Content duplication can happen in many ways, including:
Duplication due to GET-parameters
Duplication with multiple URLs due to CMS (i.e. www or non www urls)
Duplication due to accessibility on different hosts/protocols. (i.e. https or http)
Duplication due to print versions of websites
Duplicate content issues occur when the same content is accessible from multiple URLs. For example, http://www.example.com/page.html would be considered by search engines to be an entirely different page from http://www.example.com/page.html?parameter=1, even though both URLs may reference the same content.
In February 2009, Google, Yahoo and Microsoft announced support for the canonical link element, which can be inserted into the <head> section of a web page, to allow webmasters to prevent these issues. The canonical link element helps webmasters make clear to the search engines which page should be credited as the original.
Begin with the source’s own compact description: “Canonical link element” is type of hyperlink. The dossier treats that line as a proposition to test through Canonical, link and element, not as a finished interpretation.
Why this record matters
The phrase “type of hyperlink” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Aug 27, 2026. The linked authority identifier is Q1033568. None of the 0 selected statements returned an explicit reference. The first chronological checks are 2012 and 2009.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Use the entry as an orientation point, then follow its citations and revision history. Names, dates and institutional relationships should be checked against the original record.
- Subject orientation
- Search vocabulary
- Locating named sources
The closest primary source, responsible institution and strongest cited specialist reference.
Three-step research path
- Establish the record: confirm the title “Canonical link element”, its source revision and the description used here.
- Expand the search: follow Canonical link element primary sources, Canonical link element archive and Canonical research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Canonical link element”?
- Which cited source is closest to the event, object or claim?
- What terminology or title could unlock a more precise catalogue search?
Search terms from this dossier
This entry incorporates text from “Canonical link element” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.