Canonical Tag Checker

What is the Canonical Tag Checker?

The Canonical Tag Checker is a free tool that validates a page's canonical tag - confirming it's present, correctly placed in the head section, that only one exists, and that it points to the URL you expect.

A canonical tag (rel="canonical") is an HTML element that specifies the preferred version of a web page, helping to prevent duplicate content issues when the same content is reachable at more than one URL.

Why is this useful?

Canonical tags tell search engines which version of a page is the one to index. When they're missing, duplicated, or pointing at the wrong URL, you can end up with duplicate content issues or the wrong page being indexed. Checking the tag confirms it's set up correctly and pointing where you intend.

Why it matters

• Prevents the same content being treated as duplicates across multiple URL
• Consolidates link equity to your preferred URL
• Tells search engines which version of a page you want indexed
• Particularly important for ecommerce and large content sites, where the same page is often reachable several ways

Common use cases

• HTTP and HTTPS versions of the same page
• www and non-www versions
• URLs with parameters, such as tracking, sorting, or filtering
• Printer-friendly or alternative versions of a page

What it checks

• The page URL and the canonical tag match
• Only a single canonical tag exists on the page
• The canonical tag is in the head section of the page

How to run a check

• Open the Canonical Tag Checker and select 'Click to Run Checker'.
• Enter the URL of the page you want to check.

• Run the check and review the results.
• Fix any issues reported, then re-run the check to confirm.

Related free tools

• To check the page's title tag at the same time, use the Meta Title Checker.

Updated on: 24/07/2026