Canonical tag checker
Find out which URL a page declares as its main version, and whether that is what you meant.
When the canonical should point elsewhere
- Parameter URLs:
/shoes?utm_source=mailshould declare/shoes. - Printer or AMP versions of an article should declare the main article.
- Syndicated copies on partner sites may declare your original.
- Near-identical product variants may consolidate onto one main product page.
Mistakes this catches
- Two or more canonical tags with different URLs (Google may ignore them all).
- Every page canonicalised to the home page, often a template bug.
- A canonical on a page that is also
noindex: mixed signals. - A canonical in the HTTP
Linkheader that disagrees with the one in the HTML.
Write a canonical tag
<link rel="canonical" href="https://example.com/shoes/running">Place it once in <head>. For multilingual sites, pair it with hreflang tags; each language version should be canonical to itself.
Questions
What is a canonical tag?
A <link rel="canonical" href="…"> element in the page head that tells search engines which URL you consider the main version of that content. Google treats it as a strong hint, not a directive, and combines it with other signals such as redirects, sitemaps and internal links.
Should every page have a self-referencing canonical?
It is a sensible default. A canonical that points to the page's own clean URL protects it from duplicates created by tracking parameters, session IDs or mixed http and www versions.
Can I use a relative URL in the canonical?
Google supports relative paths but recommends absolute URLs, because a relative path on the wrong host or protocol can point at an address you did not mean.
Why is Google ignoring my canonical?
Common reasons: the canonical points to a page that redirects, returns an error or is noindexed; the pages are not actually duplicates; there are several conflicting canonical tags; or internal links and the sitemap point to a different URL than the canonical.