// glossary entry

Canonical Tag

What is a canonical tag?

A canonical tag is an HTML link tag in the head section that signals to search engines the preferred ("canonical") URL when content is accessible via multiple URLs. Typical examples include HTTP/HTTPS variants, www/non-www versions, session IDs, tracking parameters, pagination, or identical product pages listed under different categories. If set incorrectly, canonical tags can lead to pages being deindexed unintentionally. At Waterproof Web Wizard, we check canonical tags during every SEO audit, incorrect canonical tags are one of the most common hidden causes of sudden traffic drops.

// synonyms

  • rel=canonical
  • Canonical Link
  • Canonical URL
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