The URL in consideration is pointed via a canonical link to a different URL, yet it has accrued traffic from organic searches according to Google Analytics and Google Search Console data for the associated accounts.
Why is this important?
Given that a canonicalized URL conveys a directive to search engines not to index the page, its receipt of organic search traffic indicates that the search engines might be overlooking the canonical directive.
What does the Optimization check?
The check is activated for any internal URL that is canonicalized when it registers any amount of clicks in Search Analytics or sessions in Google Analytics.
Information is gathered via API from Google Search Console and Google Analytics for the linked Property/View and within the defined time frame.
Examples that trigger this Optimization:
Take for example the URL https://example.com/page-a which has amassed search traffic.
The check will flag this URL if it employs a canonical tag to any other URL as shown below:
Canonical tag in the HTML <head> element pointing to another internal URL:
<!doctype html><html lang="en"> <head> <title>Example Title</title> <link rel="canonical" href="https://example.com/page-b" /> ... </head> <body>...</body></html>
OR a canonical tag in the HTML <head> element pointing to an external URL:
<link rel="canonical" href="https://differentwebsite.com/page-a" />
OR a canonical tag in the HTTP header pointing to a different URL:
HTTP/... 200 OK...Link: <https://example.com/page-b>; rel="canonical"
How do you resolve this issue?
Recollecting that traffic data is historical and our crawl is in real time can help clarify if the URL was previously indexable but has now been canonicalized.
Assuming the above is not true, you'll need to figure out why search engines are indexing a URL that should not be, due to the canonical tag.
Google may choose to ignore a canonical tag if they deem another URL more suitable. If you suspect this, review the Google Search Console for any 'Google chose different canonical than user' notices.
Google's decision-making on the 'correct' canonical can depend on several factors:
Specification of canonicals for non-duplicate pages
Link equity comparison between canonical and original URLs
Inclusion of the canonicalized URL in XML Sitemaps
Redirect status of the canonical's URL
Volume of external inbound links to the canonical URL
Presence of conflicting robots directives (e.g., noindex, disallow)
An inconsistency with these elements can prompt Google to opt for a divergent canonical, which must be corrected to resolve the issue.