Canonical Checker
Fetch canonical tag, og:url, and x-default hreflang from any URL, and flag the inconsistencies.
Free, no sign-upUpdated
Use the tool
What it checks
Three signals that should all point to the same canonical URL:
- rel="canonical": tells Google which URL should rank
- og:url: tells Facebook/social platforms which URL to attribute shares to
- x-default hreflang: the fallback URL for users with no matching locale
When they don't match
A canonical pointing to /page-a while og:url points to /page-b splits link equity and social share counts between two URLs. Google ranks one; Facebook credits the other. This is common after migrations and quietly costs you.
How to use it
- Enter the URL you want to check
- Review the three tag values and the self-reference status
- Check the Issues panel: any mismatch between canonical and og:url is flagged
- Fix the mismatch at the template level, then re-run on a sample of your key pages
When to run it
On every URL you're actively acquiring links to, you want links credited to the right page. After publishing syndicated content anywhere. During a technical audit when you suspect duplicate content. After every CMS migration: canonical misconfigurations are one of the most consistent post-migration side effects.
Frequently asked questions
Is this canonical checker free?
Yes. It runs in your browser with no signup and no limits.
What should a canonical tag point to?
Usually the page itself, a self-referencing canonical, unless the page is a deliberate duplicate of another URL that should rank in its place.
Does a canonical tag guarantee indexing?
No. It is a strong signal, not a directive. Google can still pick a different canonical when your other signals, like internal links, sitemaps, and redirects, point elsewhere.
Is this the same as a canonical tag checker?
Yes, "canonical checker" and "canonical tag checker" mean the same tool. This one goes a step further than a plain tag reader by cross-checking the canonical against og:url and x-default hreflang, since those three drift out of sync more often than any single one breaks on its own.
Related tools: hreflang checker, Google index checker, and bulk redirect checker. Background reading: keyword cannibalization.