SEO & Web
What Is Canonical URL?
A canonical URL tells search engines which version of a page is the "master" copy when the same content is reachable at multiple addresses.
A canonical URL, declared with a <link rel="canonical"> tag, identifies the preferred version of a page when identical or very similar content exists at several URLs — for example with and without trailing slashes, with tracking parameters, or in printer-friendly versions.
Without canonicals, search engines may split ranking signals across duplicates or index the wrong version. Every indexable page should declare a canonical, even if it simply points to itself.