- Category
- Technical SEO
- Level
- Intermediate
- Also called
- Canonical tag, rel=canonical
- Tag
- <link rel="canonical" href="…">
- Treated as
- A strong hint, not a command
- Check it free
- Meta Tag Checker
What is a canonical URL?
The same content can often be reached at several addresses: with and without www, with tracking parameters, with a trailing slash, or through filters. Search engines pick one version, the canonical, to index and rank, and consolidate signals like links onto it. You suggest your preferred version with a canonical tag in the page's head:
<link rel="canonical" href="https://example.com/shoes/trail-runner">Google treats the tag as a strong hint. It can choose a different canonical if other signals (redirects, internal links, sitemaps) disagree.
Best practices
- Give every indexable page a self-referencing canonical.
- Use absolute URLs.
- Keep signals consistent: link internally to the canonical and list it in the sitemap.
- Use a 301 redirect instead when the old URL doesn't need to exist.
Common mistakes
- Pointing every page's canonical at the home page.
- Canonicals to URLs that redirect, 404 or are noindex.
- Several conflicting canonical tags on one page.