Canonical URL

Definition

A canonical URL (specified via the rel='canonical' link element) tells search engines which version of a page should be treated as the authoritative source when multiple URLs contain identical or very similar content. This consolidates link equity and prevents duplicate content issues. For example, if the same product page is accessible at /products/shoes, /products/shoes?color=blue, and /category/shoes, you'd set the canonical to /products/shoes. Search engines will then consolidate ranking signals to that URL. Self-referencing canonicals (a page pointing to itself) are considered best practice. Canonical tags are suggestions, not directives — Google may ignore them if they seem incorrect.