Let’s learn how to fix canonical points to canonicalized URL errors that might prevent a site from being indexed.
What Does using canonical URL to point to canonicalized page Mean?
“Using canonical URL to point to canonicalized page” means that a URL containing a canonical element points to another URL as canonical.
The rel=canonical tag sends a signal to the search crawlers about what page out of several similar ones is the most important. The search signal should be interpreted unequivocally: of all possible pages with similar content, canonical should be the only one.
Of all website pages with similar content, it is recommended to choose one canonical page. The search engine will crawl it more often than others and display it for user queries. Other pages with similar content are considered copies of the canonical page.
It is believed that if you don’t set canonical, the search engine will choose a canonical page or consider these URLs equal. In fact, Google may select a canonical page even if it is already defined. This may be caused by certain signals that are noticed by the search engine.
What triggers this issue?
A canonical page cannot point to another page as the primary page.
If pages send mixed signals about canonicalization, the search engine may misinterpret them.
Canonical page A points to canonical page B, and page B points to page A.
Canonical page A points to canonical page B, page B redirects crawlers to page A.
Canonical page tags are linked (A refers to B, B refers to C, C refers to D).
In such cases, the search engine may not only misinterpret canonical signals but also ignore them.
How to check the issue?
A canonical tag can link to itself, but it cannot link to other canonical tags. Find canonical pages on your website through analytics services and check if they are formatted correctly.
In Search Console, use the URL Checker tool to do this.
Use rel=canonical when the site has similar or identical content, when updating older publications, for pages with the same search intent.
Canonical pointing to another canonicalized URL check is good for your website but not enough to get good SERP positions!
To detect not only the issue but other kind of site level and page level problems, just make the full site audit.
Why is this important?
If a site sends mixed signals, the search engine may misinterpret it or ignore it altogether. It will then choose the canonical page at its own discretion based on other signals, such as page quality, preferred URL format, Sitemap mention, use of HTTPS.
This can result in problems with site page indexing.
The search engine will not necessarily make the right choice. As a result, inappropriate content will be displayed for user queries. Ultimately, this will lead to loss of traffic and lower positions.
How to fix the issue?
Specify the canonical page using one of the methods approved by Google: https://developers.google.com/search/docs/advanced/crawling/consolidate-duplicate-urls?hl=en.
Among the recommended options described in the Google guide for developers are:
- using the rel=canonical tag;
- including the rel=canonical field in the HTTP header of the page;
- adding canonical pages to the Sitemap file.
If the page is relocated to a new URL, you can apply redirect and canonicalize the new version of the page.