Why it matters
Google can follow canonical chains but strongly recommends pointing every link at a single canonical page. Said at Search Central Live by a community speaker: a canonical loop leaves a group with no leader at all. The leader should carry no noindex, return no error, not be blocked in robots.txt and not redirect; a leader that visitors cannot reach through links asks Google to index a page humans cannot reach.
How to meet it
Resolve each canonical target to its final URL when pages are generated, and update canonicals to the new final URLs after migrations or host changes. Never canonicalise to a URL that redirects, returns non-200, carries noindex or is disallowed. Make the canonical target the URL that internal links use, fixing whichever of the two is wrong.
How to test it
Canonical audit in a crawler: group URLs by the final URL their canonicals and redirects lead to, and flag groups with more than one hop, a loop, several canonicals on one page, or a leader that is noindexed, blocked, non-200, redirecting or without internal links.
How Regensbot covers it
Decided automatically once Regensbot crawls your verified site.
The crawl is polite: sitemap first, one request per second per host. A problem it finds is definite, and “none found” passes only on a complete crawl.
Sources
Google documents03
- 01Specify your canonicalSearch Central blog (12 February 2009) (opens in a new tab)
- 025 common mistakes with rel=canonicalSearch Central blog (8 April 2013) (opens in a new tab)
- 03How to specify a canonical URL with rel="canonical" and other methodsGoogle Search Central (opens in a new tab)
Claims in the knowledge base08
- D2-C420SourceLightning session E: Managing Duplicates and Site MovesGoogle's documentation
- D2-C419ConsistentLightning session E: Managing Duplicates and Site MovesSaid on stage
- D2-C438ConfirmedLightning session E: Managing Duplicates and Site MovesSaid on stage
- D2-C432ConsistentLightning session E: Managing Duplicates and Site MovesSaid on stage
- D2-C424UndocumentedLightning session E: Managing Duplicates and Site MovesSaid on stage
- D2-C427ConsistentLightning session E: Managing Duplicates and Site MovesSaid on stage
- D2-C416n/aLightning session E: Managing Duplicates and Site MovesThe author's interpretation
- D2-C423n/aLightning session E: Managing Duplicates and Site MovesThe author's interpretation
Claim IDs refer to the Search Central Live 2026 knowledge base. The knowledge base (opens in a new tab)
- Confirmed
- Google's documentation states the same thing.
- Consistent
- Google's documentation supports it without stating it.
- Undocumented
- Said or shown at the event, not in the documentation.
- Source
- The claim is the cited document itself.
- n/a
- Nothing to verify: a quotation, framing, opinion or analysis.