What is a canonical tag?
A canonical tag tells a search engine which URL is the preferred version of a page when several URLs show similar content.
It resolves duplication you cannot avoid: tracking parameters, pagination, printer versions, the same product under two categories. Pointing them all at one canonical consolidates the signals rather than splitting them.
What it does not do is make substantially similar pages acceptable. A canonical is a hint about which duplicate to keep, not a defence for having produced them, and Google may choose a different canonical than the one declared. Search Console reports that as Duplicate, Google chose different canonical than user, which is a content judgement rather than a markup error.
Related
- IndexationIndexation is whether a search engine has stored your page and is willing to return it. Being crawled is not the same as being indexed, and being indexed is not the same as ranking.
- Thin contentThin content is a page that exists to be indexed rather than to be read. Google's test is purpose and added value, not word count.
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