Why it matters
Broken canonical tags can make the wrong pages show up in search results, and a broken canonical setup does not fail visibly: pages load normally while the choice of URL passes to the search engine. Checking canonicals pair by pair misses chains, loops and leaders that nobody links to.
How to meet it
Crawl with a tool that groups URLs by canonical leader and flag chains, loops, multiple canonicals, leaders that are non-200, noindexed, blocked, redirecting or unlinked, and groups that mix languages. Compare user-declared and Google-selected canonicals in URL Inspection for samples.
How to test it
The scheduled crawl report shows zero canonical errors, and the "Duplicate, Google chose different canonical than user" reason in the Page indexing report trends down.
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 documents02
- 01Fix canonicalization issuesGoogle Search Central (opens in a new tab)
- 02How to specify a canonical URL with rel="canonical" and other methodsGoogle Search Central (opens in a new tab)
Claims in the knowledge base05
- D2-C401ConfirmedLightning session E: Managing Duplicates and Site MovesSaid on stage
- D2-C404n/aLightning session E: Managing Duplicates and Site MovesThe author's interpretation
- D2-C398UndocumentedHandling web duplicationSaid on stage
- D2-C416n/aLightning session E: Managing Duplicates and Site MovesThe author's interpretation
- D2-C408n/aLightning session E: Managing Duplicates and Site MovesSaid on stage
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.
- Undocumented
- Said or shown at the event, not in the documentation.
- n/a
- Nothing to verify: a quotation, framing, opinion or analysis.