For webpages which may duplicate some or all of their content with other pages (for legitimate reasons), the canonical URL is the URL of the page which search engines should link to. This tag is used for canonical 301 redirects and other methods. See the [rel-canonical] tag for more information on rel="canonical".

For example, a particular product in an online shop may be reached through two different URLs, e.g. /product/18274 and /special-offers/18274.

One way of specifying which is canonical is by using tags. All pages should have the following HTML in the header:

<link rel="canonical" href="http://www.example.com/product/18274" />

Another way of specifying which is canonical is by implementing s from the non-canonical URL to the canonical URL:

/special-offers/18274 -> /product/18274

history | excerpt history