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Canonical Checker

Check canonical tags and HTTP Link canonicals on our server so you can spot duplicates, conflicts, and wrong targets. Nothing is stored.

This check runs on our server. The address you enter is used only for this check and is not stored.
Updated

This check runs on our server. The address you enter is used only for this check and is not stored.

Mode: Canonical check

Tick the box to show you are not a robot, then press Check.

How to use the Canonical Checker

  1. Enter the full page URL.
  2. Start the check.
  3. Review the canonical source, target URL, target status, and any conflicts the report finds.

How it works

This check runs on our server. The page address is used only for this check and is not stored.

The checker fetches one page, reads canonical values from the HTML and the HTTP Link header, normalizes relative targets against the final URL, and tests the canonical target with a follow-up request.

It also looks for common problems: more than one canonical, a canonical that points elsewhere on a near-identical page, a canonical that conflicts with noindex, or a target that switches protocol or host unexpectedly.

Examples

  • A page at http://example.com/page can return a canonical to https://www.example.com/page, which may be correct if that is the preferred version.
  • A page with two canonical tags is flagged because search engines may ignore both or pick one arbitrarily.
  • A canonical that points to a 404 page is reported as a broken target.

Limitations

  • The checker reads one page and its canonical target. It does not compare whole duplicate clusters across a site.
  • JavaScript-added canonicals are not seen because the page is not rendered in a browser.
  • A canonical can be technically valid but still be the wrong editorial choice for your content. The tool reports the mechanics, not your content strategy.

Frequently asked questions

Should the canonical usually point to the same page?

Yes. Most indexable pages should have a self-referencing canonical unless they are true duplicates of another preferred URL.

Can a noindex page have a canonical tag?

It can, but that combination often creates mixed signals. If a page should not be indexed, review whether it needs a canonical at all.

Do relative canonical URLs work?

They can be resolved, but absolute canonicals are clearer and easier to audit.

Often used together with the Canonical Checker.

  • Website SEO Analyzer

    Checks one page for SEO basics, response details, tags, headings, links, and structured data without running JavaScript.

  • Robots.txt GeneratorDeveloper Tools

    Creates robots.txt rules for search and AI crawlers and tests URLs against them.