Free Canonical URL Checker

What this tool checks

This tool inspects the canonical URL setup of your page. It checks whether a canonical tag is present in the page's HTML head, whether it points to itself (self-referencing) or another URL, whether the canonical URL is absolute vs relative, and whether it's consistent with the page's declared URL. It also checks for multiple canonical tags (only the first is honored) and canonical tags set via HTTP headers.

Why it matters

Canonical tags tell search engines which version of a URL is the 'master' copy, consolidating ranking signals from duplicate or near-duplicate pages. Without a canonical tag, Google has to guess which URL to rank — and it often guesses wrong. E-commerce sites with faceted navigation, blogs with tag pages, and any site with URL parameters are especially vulnerable to duplicate content fragmentation.

Common issues we find

• Missing canonical tag, leaving duplicate content decisions to the search engine
• Canonical pointing to a different domain or environment (e.g., staging URL left in production)
• Using a relative path instead of an absolute URL, causing inconsistent resolution
• Multiple conflicting canonical tags — only the first is used, rest are ignored
• Canonical pointing to a redirected URL instead of the final destination