Canonical tag checker

What is a Canonical Tag Checker?

The Canonical Tag Checker looks for a <link rel="canonical"> tag on a webpage and reports which URL it points to. The canonical tag tells search engines which version of a page is the "master" copy when duplicate or near-duplicate content exists.

Common Canonical Issues

• Missing canonical — Pages with URL parameters (tracking tags, session IDs, sort orders) can be indexed as separate duplicate pages without one.
• Self-referencing vs cross-domain — Most pages should canonicalize to themselves; cross-domain canonicals are used for syndicated content.
• Conflicting signals — A canonical tag pointing to a different URL than what's in the sitemap or internal links can confuse crawlers.