Technical SEO

Canonical Tag

A canonical tag is an HTML element (rel="canonical") that tells search engines which version of a page is the original when near-duplicate URLs exist.

An ecommerce product reachable through three filter URLs should point all three at one canonical, so ranking signals consolidate on a single page instead of splitting. Missing or conflicting canonicals are a common cause of duplicate-content dilution. It is a strong hint to search engines, not an absolute command.

Canonicals fail through disagreement more often than through absence. The tag says one thing, the internal links point somewhere else, the sitemap lists a third URL, and the redirect chain ends at a fourth. Google resolves the conflict on its own, and the URL it picks is frequently not the one you wanted. Search Console URL Inspection reports the chosen canonical, which is the only reliable way to see what it decided. Before adding canonicals, make sure the rest of the site agrees with them, because a tag arguing against every other signal on the site usually loses.