Why canonical URLs matter
A page can be reachable through more than one URL—for example, with tracking parameters, alternate hostnames or slash variants. A canonical link tells search engines which URL you prefer to represent a set of substantially similar pages. It is a signal, not an absolute command: search engines can choose another canonical if other evidence disagrees.
How to interpret the checker result
A missing canonical may be intentional, but many indexable pages benefit from an explicit self-referencing canonical. More than one canonical tag is usually a sign to inspect templates or plugins. A mismatch can arise from staging hosts, an incorrect trailing slash, HTTP versus HTTPS, or a canonical copied from another page. Review the final rendered HTML and redirects as well as the source.
Canonical is not a substitute for good URL hygiene
Keep internal links, redirects, sitemap entries and canonical URLs consistent. Avoid using a canonical to merge pages that serve different intent or materially different content. For faceted or parameterized URLs, decide which variants should be discoverable and make that policy consistent across the site.
Frequently asked questions
Should every page have a self-referencing canonical?
It is a common, useful pattern for indexable pages, but page architecture matters. Ensure each canonical points to the intended version and is consistent with redirects and internal links.
Does a canonical tag guarantee which URL Google indexes?
No. Canonicalization is a signal. Google may select a different URL based on the overall evidence it sees.
Does this check the live page source?
No. Paste the source yourself. The tool runs locally and does not make a request for the URL you enter.