Check if your URL follows canonical best practices

What is a canonical URL?

A canonical URL is the single preferred version of a web page when multiple URLs serve identical or near-identical content. Search engines use the canonical URL to consolidate indexing signals and avoid penalising duplicate content.

The most common duplicates are protocol and subdomain variants:

  • http://example.com
  • https://example.com
  • http://www.example.com
  • https://www.example.com

All non-canonical variants should redirect to the one true URL using a permanent 301 or 308 redirect, and that page should declare itself canonical with a <link rel="canonical"> tag.

What does iscanonical check?

  • 🔁
    Redirect to canonical URL Does the non-canonical variant (flipped protocol and www) redirect to your URL?
  • ✅
    Redirect status code Is the redirect permanent (301 or 308) rather than a temporary 302?
  • 🔗
    Redirect chain length Does the redirect resolve in a single hop, or does it chain through multiple steps?
  • 🏷️
    Canonical link tag Does the page include <link rel="canonical" href="…"> in its <head>?
  • ⏱️
    Meta refresh Is a <meta http-equiv="refresh"> tag used instead of a proper HTTP redirect?