Canonical URL.
Learn what Canonical URL means in modern search and SEO.
The preferred version of a page URL, specified via a rel=canonical tag to consolidate ranking signals when duplicate or similar content exists.
A canonical URL is the authoritative version of a web page that you want search engines to index and rank when multiple URLs serve similar or identical content. Specified using `<link rel='canonical' href='...' />` in the page's `<head>`, it tells crawlers to attribute link equity and ranking signals to the canonical URL rather than any duplicate versions.
When Canonicalization Is Needed
Canonical tags are essential for managing: content accessible via multiple URLs (www vs non-www, HTTP vs HTTPS, trailing slash vs no trailing slash, URL parameters); syndicated content published on other sites; e-commerce pages accessible through multiple category paths; and pagination or filtered views that create near-duplicate pages. Without proper canonicalization, duplicate content splits link equity and can cause indexing issues.
Canonical Tags vs. Redirects
A canonical tag is a suggestion to search engines, not a directive—they may ignore it if they determine another URL better represents the content. A 301 redirect is a stronger signal that definitively sends users and crawlers to the canonical version. For pages you control and want to fully consolidate, 301 redirects are preferable; canonical tags are better for externally accessible duplicates you can't redirect.
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