The canonical URL is the one address a page declares as its true copy, in <link rel="canonical">, so that duplicates (www and non-www, tracking parameters, syndicated copies) are consolidated onto it.
Indexes put a page's standing on its canonical. A canonical pointing elsewhere gives the page away; none at all splits it across duplicates.
View source and compare rel="canonical" with the address bar.
Checked by Reflexa: Do your canonical tags point to the page itself? — part of the 23 checks on every page check.
The canonical URL is the one address a page declares as its true copy, in <link rel="canonical">, so that duplicates (www and non-www, tracking parameters, syndicated copies) are consolidated onto it.
Indexes put a page's standing on its canonical. A canonical pointing elsewhere gives the page away; none at all splits it across duplicates.
View source and compare rel="canonical" with the address bar.
The free page check runs the 23 checks on your public pages — the terms on this page, observed on your pages.