On-Page SEO

Canonical URL

Quick Definition

A canonical URL is the single 'master' URL for a piece of content when duplicates or near-duplicates exist — declared via the rel="canonical" link tag, HTTP header, or sitemap.

In context

Canonical URLs solve the duplicate-content problem: when the same content is reachable at multiple URLs (with/without www, http/https, query parameters, tracking codes, AMP versions, paginated archives), the canonical signals which URL should accumulate ranking signals and appear in results. Best practice: declare a self-referencing canonical on every page; point near-duplicates to the master; never canonical to a 3xx, 4xx, or noindex page; and audit canonicals after any URL-structure change. See also canonical-tag.

Example

A Toronto SEO services page reachable at /seo-services/, /seo-services/?utm_source=newsletter, and /seo-services/?ref=linkedin all declare canonical: /seo-services/ — so all three URLs consolidate ranking signals to the master.

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