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Canonical URL Checker

Find the canonical tag on any page, see which URL it names as the original, and confirm that address actually loads.

Fetching and analysing the page…

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Canonical URL Checker - results and guide

What the Canonical URL Checker checks

  • The rel=canonical link tag and any canonical sent in the HTTP Link header
  • Missing, empty, repeated or conflicting canonical tags
  • A canonical placed in the body, where Google ignores it
  • Whether the canonical is self-referencing or points to another page or domain
  • Relative URLs, fragments, tracking parameters and http on an https page
  • Whether the canonical target returns 200, redirects or fails
  • Conflicts with noindex and with og:url

What is a canonical URL?

The same content is often reachable at several addresses: with and without a trailing slash, with tracking parameters, in a sorted or filtered view, over http and https. A canonical tag, <link rel="canonical" href="...">, tells search engines which of those addresses is the original, so ranking signals are combined on one URL instead of being split across copies.

Most pages should name themselves, which is called a self-referencing canonical. Pointing to a different page says "index that one instead of me", which is right for duplicates and harmful on a page you want in search.

How search engines treat it

The canonical is a strong hint, not a command. Google ignores it when the tag is in the body, when a page has several different canonicals, or when the target redirects, returns an error or has different content. It also weighs your internal links, sitemap and redirects, so keep all of them consistent with the canonical.

Use the absolute URL including https://. If the page should not be indexed at all, use noindex instead and check it with the Noindex Tag Checker.

How to use the Canonical URL Checker

  1. Enter the address of the page you want to check. You can leave out https://.
  2. Press Check canonical. The page is fetched from our servers, the way a search engine crawler would fetch it.
  3. Read the findings from top to bottom: problems first, then warnings. Each one says what to change.

Common problems and how to fix them

Two different canonical tags

A theme and a plugin are usually both adding one. Remove one source so the page has a single tag.

The canonical points to the home page everywhere

A template is printing a fixed URL. Every page then tells search engines it is a copy of the home page. Generate the tag from each page's own address.

The canonical target redirects

Update the tag to the final URL. This is common after a move to https or a change of trailing slash.

Frequently asked questions

Does every page need a canonical tag?
It is not required, but a self-referencing canonical on every indexable page is good practice. It protects against duplicates created by parameters and tracking links.
What is a self-referencing canonical?
A canonical tag whose URL is the page's own address. It confirms that this page is the version to index.
Can a canonical point to another domain?
Yes. That is how syndicated articles credit the original. Use it only when the other page really is the source.
Should I use a canonical or a 301 redirect?
Use a redirect when visitors should not see the duplicate at all. Use a canonical when both versions must stay reachable, such as filtered product lists.

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