Cross-Domain Canonical

A cross-domain canonical is a canonical tag that points from a page on one domain to a page on a different domain. It tells search engines that the other site holds the preferred version of the content, so ranking signals should be consolidated there.

Written by Paul Hoda, SEO consultant since 2005. Last updated 8 November 2026.

How it works

A normal canonical tag points to a URL on the same site. A cross-domain version simply uses another hostname, for example a page on shop-two.co.uk with <link rel="canonical" href="https://www.shop-one.co.uk/product/">.

Google has supported cross-domain canonicals for many years, and Bing supports them too. Like all canonicals, they are a hint. Search engines usually follow them when the pages are very similar, and may ignore them when the content differs.

When it is useful

  • Several sites you own: for example regional storefronts or brand sites that share identical product descriptions.
  • Moving content: when a redirect is not possible, a cross-domain canonical can point to the new home as a fallback.
  • Republishing your own articles: such as cross-posting a blog post to a platform that lets you set the canonical URL.
  • Printer-friendly or alternative domains that duplicate main-site content.

Its limits for syndication

Many publishers used to ask partners to add a cross-domain canonical when republishing their articles through content syndication. Google’s guidance has since changed: it says the canonical is not recommended for this case because syndicated pages often differ, and suggests partners use a noindex tag if the original publisher wants to avoid competing with them. A canonical may still help, but it is no guarantee.

How to implement it

  1. Only use it when the content is the same or nearly the same.
  2. Use an absolute URL that returns a 200 status and is indexable.
  3. Do not point to a URL that itself canonicalises or redirects elsewhere.
  4. For pages you control on both domains, a 301 redirect is stronger if users do not need the duplicate.
  5. Monitor the duplicate site in Search Console: excluded pages with a note about an alternate canonical show it is working.

Example

A company runs two websites: a main brand site and a trade site for wholesale buyers. Both show the same 400 product pages with identical descriptions, because the trade site only adds bulk pricing after login. The company wants the brand site to rank in public search results.

Each product page on the trade site gets a canonical tag pointing to the matching product URL on the brand site. Over time, Google tends to index the brand site versions and treats the trade pages as duplicates. Trade customers still use their own site as normal. If the company later merged the two sites completely, it would replace the canonicals with redirects, because redirects send both users and search engines to the single preferred page.

Common mistakes and risks

  • Canonicalising international SEO pages to one country site. Translated or localised pages should use hreflang instead.
  • Accidentally pointing a whole site to another domain after copying a template or staging setup.
  • Expecting a partner to keep the tag in place forever without checking.
  • Using it on pages with different content, which Google will likely ignore.

Further reading: Google on consolidating duplicate URLs.

Key Takeaways

  • A cross-domain canonical points to the preferred version on another website.
  • It works best when the pages on both domains are near identical.
  • Search engines treat it as a hint and may ignore it if the content differs.
  • Google now suggests noindex rather than canonicals for syndication partners.
  • Do not use it for translated or localised pages, which need hreflang.

Related Terms

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