Canonical URL Checker

Check canonical tags to avoid duplicate content issues.
HTML Input
Runs in your browser
Tip: use View Source and paste the full HTML.
Result
Waiting
Paste HTML and click “Check Canonical”.
    Privacy note: the checker runs locally, and your HTML is not uploaded.

    What canonical tags do

    Canonical tags tell search engines which URL is the preferred version when similar pages exist.

    Common issues

    Missing canonical tags can lead to duplicate content. Multiple canonicals create ambiguity.

    Best practices

    Use absolute URLs and ensure the canonical points to the correct page version.

    How to check canonical tags

    Paste HTML and review the canonical URL.

    1. Paste the page HTML into the input.
    2. Click Check Canonical.
    3. Review the detected canonical URL.

    FAQ

    Does this fetch the URL?
    No, paste the HTML source directly.
    What if there are multiple canonicals?
    You should keep only one canonical tag per page.
    Is my HTML uploaded?
    No, everything runs locally.