Canonical tags are one of the easiest SEO details to get subtly wrong — a relative URL, a duplicate tag, or a canonical pointing to the wrong page can quietly confuse search engines about which version of a page to index. This tool checks the common mistakes in seconds.
What Is the Canonical URL Checker?
Paste your page’s HTML (full document, <head> fragment, or just the tag) along with the current page URL, and the tool reports whether exactly one canonical tag exists, whether it’s an absolute URL, and whether it’s self-referencing — flagging duplicates and relative URLs as issues.
How to Use It
- Open the tool at /tools/canonical-url-checker.
- Paste your page’s current URL.
- Paste the HTML (or just the
<head>section) containing your canonical tag. - Review the pass/fail checklist for common canonical mistakes.
Key Features
- Detects missing or duplicate canonical tags, both of which can confuse search engine indexing.
- Flags relative canonical URLs as a warning, since Google recommends absolute URLs.
- Confirms self-referencing canonicals, the recommended default for most non-duplicate pages.
- Purely static analysis — no network requests, so nothing about your site is ever sent anywhere.
When to Use This Tool
- Before publishing a new page template to confirm canonical tags render correctly.
- Auditing existing pages for duplicate-content SEO issues.
- Debugging unexpected search engine indexing behavior tied to canonicalization.
Try It Now
Open Canonical URL Checker directly, or press ⌘K and type the tool name from anywhere on the site.
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