Canonical URL Checker
Free canonical URL checker — fetch any page and verify its rel=canonical tag, spot self-referencing or conflicting canonicals, and catch indexing issues.
About the Canonical URL Checker
The canonical tag tells search engines which URL is the master version of a page, consolidating ranking signals and preventing duplicate-content dilution. This free canonical URL checker fetches any page server-side and reports exactly what canonical it declares and whether that setup is healthy.
It extracts the rel=canonical link from the head, compares it against the page's own URL, and flags common problems: a missing canonical, a canonical pointing to a different page, multiple conflicting canonical tags, or a relative canonical that should be absolute. Each finding comes with a clear pass, warn or fail verdict.
Getting canonicals right is one of the highest-leverage technical SEO fixes — wrong ones can quietly keep your best pages out of the index. Use this tool to confirm each important page self-references correctly and that intentional canonicals point where you expect.
How to Use the Canonical URL Checker
- 1Enter the page URL you want to check.
- 2Click Check canonical to fetch the page server-side.
- 3Read the declared canonical and its verdict.
- 4Fix missing, relative or conflicting canonicals and re-check.
Frequently Asked Questions
What is a canonical URL?
A canonical URL is the address you designate as the definitive version of a page when the same or similar content is reachable at several URLs. Declaring it with a rel=canonical link tells search engines to consolidate ranking signals onto that one URL and treat the others as duplicates.
What is a self-referencing canonical?
A self-referencing canonical is a page whose canonical tag points to its own URL. This is the recommended default for most pages — it removes ambiguity, guards against duplicate versions created by tracking parameters, and confirms to crawlers that this exact URL is the one to index.
What problems does a wrong canonical cause?
A canonical pointing to the wrong page can cause search engines to drop the correct page from the index in favour of another, silently costing you traffic. Missing canonicals leave duplicates to compete, and conflicting tags confuse crawlers. Getting them right is critical to reliable indexing.
Should the canonical URL be absolute?
Yes. Google recommends absolute canonical URLs (including the full https://domain.com/path) rather than relative paths, because relative canonicals can be misinterpreted. This checker flags relative canonicals so you can switch them to the full absolute form.
Can a page have more than one canonical tag?
It should have exactly one. Multiple canonical tags are conflicting signals, and search engines may ignore all of them or pick one unpredictably. This tool detects duplicate canonicals so you can remove the extras and leave a single, clear declaration.