Canonical Tag Checker
Paste a URL to inspect its canonical tag and detect potential duplicate-content issues.
Paste any page URL (with or without parameters). The tool reports the detected canonical (demo).
Inspecting…
Canonical report
What is a canonical tag?
The rel="canonical" link element tells search engines which URL is the preferred (canonical) version of a page when multiple URLs serve similar or identical content. Correct canonicals consolidate ranking signals and prevent duplicate-content dilution.
Self-referencing
Most pages should point to themselves as canonical when they are the primary version.
Cross-domain
You can canonicalize to another domain (e.g. after a migration or for syndicated content).
HTTP header
Canonicals can also be sent via the Link HTTP header for non-HTML resources.
How to use this tool
- Paste the full URL you want to inspect (including query parameters if present).
- Click Check Canonical to see the reported canonical target and status (demo data).
- Copy or download the result and fix any mismatches in your CMS or templates.
Best practices
- Use absolute URLs in the canonical tag.
- Ensure the canonical URL returns a 200 status and is indexable.
- Avoid chains and loops (A→B→A).
- Align canonicals with sitemap and internal linking.
Frequently asked questions
Does Google always follow the canonical?
Google treats it as a strong hint, not a directive. Conflicting signals (sitemaps, redirects, internal links) can override it.
Should every page have a canonical?
Yes—self-referencing canonicals are recommended even when no duplicates exist.