Glossary · Canonical URL
Canonical URL
The URL designated as the primary version of a page when multiple URLs return similar content. Set with a `rel="canonical"` link tag.
Canonical tags consolidate ranking signals across duplicate or near-duplicate URLs. If a page is reachable at `/page`, `/page/`, `/page?utm_source=email`, and `/page?ref=twitter`, the canonical points all four to the same primary URL.
Mistakes here are common: canonicals pointing to the wrong page, canonicals on every page pointing to the homepage, missing trailing-slash consistency.