About the Canonical Tag Checker
A canonical tag tells search engines which URL you consider the main version of a page. It is a strong hint rather than a command, and mistakes are common: two canonicals that disagree, a relative URL, an HTTP target on an HTTPS site, or a canonical pointing at a page that redirects. This canonical tag checker fetches a public URL and reads the canonical from both the HTML and the HTTP Link header.
It reports whether one canonical is present, whether it is absolute and HTTPS, whether it points to the page itself or elsewhere, and whether it matches og:url and the page's hreflang annotations. A self-referencing canonical is normal for most pages. If the canonical points elsewhere, make sure that is intentional, because Google may drop this URL from the index in favour of the target.
How to use it
- Enter the URL of the page you want to check.
- Run the check to read canonicals from the HTML head and HTTP headers.
- Review warnings for multiple, relative, non-HTTPS or conflicting canonicals.
- Correct the canonical in your CMS or SEO plugin and re-check.
Frequently asked questions
Should every page have a self-referencing canonical?
It is a widely recommended practice. A self-referencing canonical helps when the same page is reached with tracking parameters, different cases or session IDs, because it states which address is the main one. It is not mandatory, and Google can choose a canonical without one, but adding it removes ambiguity at very little cost.
What happens if a page has two different canonical tags?
When a page declares conflicting canonicals, for example one in the HTML and another in the HTTP header, or two tags from different plugins, Google may ignore both and choose a canonical itself. Keep exactly one canonical per page, from one source, and make sure every method you use points to the same URL.
Why did Google pick a different canonical than mine?
Canonical tags are hints. Google also weighs redirects, internal links, sitemap URLs, HTTPS and content similarity. If your declared canonical conflicts with those signals, for example most internal links point to another version, Google may choose differently. Make all signals point to the same URL and check Search Console's URL Inspection to see Google's choice.