Canonical Tag

A canonical tag (rel=”canonical”) is an HTML snippet placed in the head section of a webpage that explicitly tells search engines which URL is the master version of that content. It is the primary defense against duplicate content penalties caused by URL parameters, session IDs, or faceted navigation. Unlike a 301 redirect, which physically moves the user, a canonical tag is invisible to the user but passes the page’s link equity to the master URL. A missing or improperly implemented canonical tag guarantees index bloat and cannibalized rankings.

Canonical Tag Simplified

A canonical tag is a hidden piece of code that points to the original version of an article or product page. It tells Google, “This page is just a copy or a slight variation; please give all the SEO credit to the main original page.”