Canonical Tag Checker
Find out which URL a page declares as canonical, in the HTML and in the HTTP headers, and whether Google can trust it.
What the tool checks
The tool fetches your page, collects every canonical it declares and then runs these tests:
- Present. Is there a
<link rel="canonical">tag or aLink: <url>; rel="canonical"response header? - Single. Multiple tags, or a tag and a header that disagree, cancel each other out.
- Absolute. The URL should include protocol and host.
- Inside the head. Google ignores canonical tags that end up in the body. That happens when something invalid earlier in the head makes the parser close the head early.
- Self-referencing or not. Neither is wrong. The tool tells you which one it is so you can confirm it matches your intent.
- Protocol and host. An https page with an http canonical, or a www page with a non-www canonical, is nearly always a leftover from a migration.
- Target returns 200. The canonical URL is fetched once. It should answer 200 directly, without a redirect or an error.
- Target is indexable. A canonical that points at a noindex page sends contradicting signals.
Common mistakes and how to fix them
Every page canonicalised to the home page
A template with a hard-coded canonical tells Google that the whole site is a copy of one URL. Google usually spots this and ignores the tag, but do not rely on it. Output the URL of the current page.
Paginated pages pointing to page 1
Page 2 of a category is not a duplicate of page 1. Give each paginated page a self-referencing canonical so the products or posts linked from deeper pages are still discovered.
Canonical to a redirected URL
After a URL change, canonicals often still name the old address. Google has to follow the redirect to work out what you meant. Update the tag to the final URL. You can trace the hops with the redirect checker.
Header and HTML disagree
CDNs and some frameworks add a canonical Link header. If your CMS prints a different tag in the HTML, you have a conflict that is invisible in the page source. The HTTP headers checker shows the raw header.
Canonical is one of several gates
A correct canonical does not help if robots.txt or a noindex blocks the page. Run the indexability checker for the full picture. When the page is clean, TurboIndex can submit it to Google and track when it gets indexed.
Questions and answers
Does every page need a canonical tag?
It is not required, but a self-referencing canonical on every indexable page is cheap insurance. It tells Google which version to keep when the same page is reachable with tracking parameters, mixed case, or with and without a trailing slash.
Will Google always respect my canonical?
No. rel=canonical is a strong hint, not a directive. Google also looks at redirects, internal links, sitemap entries and https. If those point at a different URL, or if the two pages are not really duplicates, Google can choose another canonical. Search Console shows this as Duplicate, Google chose different canonical than user.
What happens when a page has two canonical tags?
If they name different URLs, Google is likely to ignore both and decide on its own. This usually happens when a theme and an SEO plugin each print a tag. The tool lists every canonical it finds so you can see where the conflict is.
Can I use a relative URL in a canonical tag?
It is valid and Google supports it, but Google's documentation recommends absolute URLs. A relative path copied to a staging host or combined with a wrong base tag resolves to an address you did not intend.
Should I combine noindex with a canonical to another page?
No. The two send opposite messages: the canonical says this page is the same as that one, and noindex says drop this page. Pick one. Use the canonical to consolidate duplicates, and noindex for pages that should not appear in search at all.