Canonical URL Checker
Conflicting canonical signals get weighted against each other and the winner is unpredictable. This shows every signal side by side.
Free · No sign-up · Reads the raw HTML a crawler sees
What a canonical tag settles
It tells search engines which URL is the real one when several serve the same content — with and without a trailing slash, with tracking parameters, with and without www, HTTP and HTTPS.
Without one, Google picks for you. It usually picks correctly and sometimes does not, and when it does not you get ranking signals split across variants of the same page.
Every page should carry a self-referencing canonical. It costs one line and removes the ambiguity permanently.
The three ways it goes wrong
Two canonical tags, because the CMS emits one and an SEO plugin emits another. When they conflict Google discards both, which is worse than having neither.
A canonical pointing somewhere else on every page — usually a template that hardcoded the homepage. This tells Google not to index any of those pages, and it is quietly catastrophic.
A canonical that disagrees with og:url or with where a redirect actually lands. Conflicting hints get weighed against each other and the outcome is unpredictable across templates.
How to use it
- Enter the page URL — Use the URL you want indexed.
- Confirm it is self-referencing — The canonical should match the URL you fetched.
- Check the signals table — og:url, the Link header and meta robots should all agree.
Frequently asked questions
What is a canonical URL?
The version of a page you want search engines to index when several URLs serve the same content. You declare it with <link rel="canonical">.
Should every page have a self-referencing canonical?
Yes. It is the simplest way to stop parameterised and trailing-slash variants from splitting your signals.
What if I have two canonical tags?
Google ignores both when they conflict. Usually one comes from your CMS and one from a plugin — remove the duplicate.
Is a canonical the same as a 301 redirect?
No. A redirect sends users and crawlers elsewhere. A canonical serves the content and asks engines to credit a different URL. Use a redirect when the page has genuinely moved.