# Cross-domain canonical

Category: [Crawling & Indexing](https://seo-geo-glossary.com/en/glossary/category/crawling-indexing/) › [Canonicals & duplicate content](https://seo-geo-glossary.com/en/glossary/category/crawling-indexing/canonicals-duplicate-content/)

A **cross-domain canonical** is a `rel="canonical"` link that points to a URL on a different domain. It tells Google that the preferred version of the content lives there. Like any `rel="canonical"` annotation, it is a strong signal, and Google may still choose another URL.

## When is it used?

The typical case is content that appears on two domains, such as an article a partner republishes. Google's documentation says the canonical element is not recommended for syndication, because the syndicated pages are often very different. Instead, Google says syndication partners should block indexing of the syndicated content.

Cross-domain canonicals are also a known sign of hacked sites. Google describes attacks that insert a cross-domain canonical pointing to spammy content into the head or the HTTP header.

## Example

A partner page republishes an article and sets:

```html
<link rel="canonical" href="https://www.example.com/blog/article/">
```

## Common mistakes

- The target is an unrelated page, such as the home page of the other domain.
- The canonical was added by someone else and nobody on your side knows about it. Check the source of pages that suddenly lose rankings.

*Diagram: Duplicate cluster and canonical URL.* Google groups identical or very similar pages into a cluster and picks one canonical URL. According to Google, redirects and rel="canonical" are strong signals and the sitemap is a weak one. Your own preference remains a hint.

## Related terms

- [Canonical tag](https://seo-geo-glossary.com/en/glossary/canonical-tag/index.md)
- [Self-referencing canonical](https://seo-geo-glossary.com/en/glossary/self-referencing-canonical/index.md)
- [Canonicalization](https://seo-geo-glossary.com/en/glossary/canonicalization/index.md)
- [Duplicate content](https://seo-geo-glossary.com/en/glossary/duplicate-content/index.md)
- [Domain](https://seo-geo-glossary.com/en/glossary/domain/index.md)

## Sources

- [Fix canonicalization issues – Google Search Central](https://developers.google.com/search/docs/crawling-indexing/canonicalization-troubleshooting)
- [How to specify a canonical URL with rel="canonical" and other methods – Google Search Central](https://developers.google.com/search/docs/crawling-indexing/consolidate-duplicate-urls)

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Last updated: October 8, 2026
URL: https://seo-geo-glossary.com/en/glossary/cross-domain-canonical/