# Canonical

> A canonical URL is the web address a search engine selects as the most representative of a set of pages with duplicate content; choosing it is called canonicalisation.

Original page: https://t10.de/en/glossary/canonical
Publisher: total10 GmbH, https://t10.de/en/glossary

The link relation behind the term was defined by the Internet Engineering Task Force (IETF), the body that develops internet standards. In [RFC 6596](https://www.rfc-editor.org/rfc/rfc6596), an informational document published in April 2012, a 'canonical' link designates one web address as preferred over resources with duplicate content.

Google's [documentation on canonicalisation](https://developers.google.com/search/docs/crawling-indexing/canonicalization) treats a site's stated preference as a hint, not a rule: a site can indicate which URL it prefers, but the search engine may choose a different page for various reasons. It [lists three methods](https://developers.google.com/search/docs/crawling-indexing/consolidate-duplicate-urls) of indicating the preference, ranked by how strongly they can influence the choice. Redirects and rel="canonical" link annotations are strong signals, while inclusion in a sitemap is a weak one. None of them is required, although a rel="canonical" link on the canonical page itself, known as a self-referential canonical, is recommended.

In our client work the subject comes up in multilingual shops. For Battle-Merchant we manage canonicals across the shop's language versions; at Cold Steel, the canonical of each brand landing page is managed individually in all four of its language versions.

## See also

- [SEO](https://t10.de/en/glossary/seo): SEO, or search engine optimisation, is the work of helping search engines understand a site's content and helping people find the site through search and decide whether to visit it.
- [hreflang](https://t10.de/en/glossary/hreflang): The hreflang attribute gives the language of a linked page and lets a site tell search engines which pages are localised versions of the same content.
- [Landing page](https://t10.de/en/glossary/landing-page): As defined in the Google Ads glossary, a landing page is the web page people arrive at after clicking an ad.

## Where the term appears

- [Technical SEO](https://t10.de/en/seo)
- [Cold Steel: brand landing pages](https://t10.de/en/portfolio/coldsteel)
- [Battle-Merchant: canonical control](https://t10.de/en/portfolio/battlemerchant)

## Sources

1. [RFC 6596: The Canonical Link Relation (April 2012)](https://www.rfc-editor.org/rfc/rfc6596), IETF / RFC Editor, accessed 2026-11-07
2. [Was ist Kanonisierung?](https://developers.google.com/search/docs/crawling-indexing/canonicalization?hl=de), Google Search Central, accessed 2026-11-07
3. [Kanonische URL mit rel="canonical" und anderen Methoden angeben](https://developers.google.com/search/docs/crawling-indexing/consolidate-duplicate-urls?hl=de), Google Search Central, accessed 2026-11-07