Canonical Tag Generator

A canonical tag tells search engines which URL is the real address of a page when several addresses show the same content. That happens constantly without anyone intending it: tracking parameters, print versions, a page reachable with and without a trailing slash, the same product listed under two categories.

The tool builds the link tag and checks it against the mistakes that quietly stop it working. A canonical must be an absolute URL, so a relative path is a problem. It should point at a page that returns 200, not a redirect. Every page should carry one canonical, and only one; two conflicting tags are ignored entirely. And the most common error of all is a template that writes the same canonical onto every page, which tells search engines your whole site is one page.

An optional hreflang section generates the alternate links for multi-language sites, including the x-default entry, with a reminder that hreflang annotations have to be reciprocal to be trusted.

• Generates the canonical link tag
• Warns about relative URLs and missing protocols
• Flags tracking parameters left in the canonical
• Self-referencing canonical helper
• Optional hreflang alternates with x-default
• Explains the reciprocity requirement for hreflang
• Copy the complete tag block

The canonical tag generator is used by writers, developers, students, marketers and anyone else who needs the job done once without installing software. Common cases include:

• Consolidating duplicate URLs onto one address
• Pointing parameterised URLs at the clean version
• Setting self-referencing canonicals across a site
• Adding language alternates for an international site
• Checking that a canonical is written correctly