Canonical tag checker
When the same content is reachable from several URLs, the canonical tells search engines which address is the original so ranking signals are not split.
What we measure
We look for <link rel="canonical"> in <head>. Missing is a warning. If it is present and points somewhere other than the audited URL, we surface that — it is only correct when the page is a deliberate duplicate.
How to set one
Use an absolute http(s) URL. Self-canonical on the preferred address. Do not point a unique page at the homepage, and do not let tracking parameters become a second indexable copy.
A canonical to another host is a strong signal you do not want this URL indexed. Use that only when you mean it.
See the full audit in your workspace