This notification means the URL has a canonical element specified in multiple locations (either in the HTML, in the HTTP header, or both).
What Does “Multiple Canonical Tags Found” Mean?
The Rel = Canonical Tag is an HTML element found in the page’s head that helps prevent duplicate content issues. Multiple Canonical Tags Found means that these links have more than one rel=canonical tag on the page.
You should specify the canonical tag only once per URL to avoid negative effects on search traffic. Doing it multiple times increases the chance of human error.
For more information on duplicate URLs, see Google Help.
A canonical URL is just a single line of code in the header of the source code, which will help you specify one of the priority URLs.
What triggers this issue?
If you find this issue, there are several canonical tags for one URL on the site. The tag can be either in HTML or in HTTP. Note that the tooltip with this error will pop up even if you have the same tags in these places.
This issue often appears after using a plugin or template that inserts the canonical tag into the page without the webmaster’s knowledge.
How to check the issue?
To check for errors on pages on your site, use the Google Search Console or another crawler to search for SEO errors.
Pages With Multiple Canonical URLs analysis is not enough to optimize your site for search engines!
Make a full audit to find out and fix your technical SEO in order to improve your SERP results.
An issue notification will be triggered for a particular URL if multiple canonical tags are set for it at once, regardless of whether they were the same or not.
You can find more information about Canonical URLs in this episode of Ask Google Webmasters.
Why is this important?
If several canonical tags are installed on one page of the site, the search engine robots will not figure out which tag contains the canonical page. As for Google, the search robot will simply ignore all the tags if it detects several tags on the same page at once. Other search engines can do the same.
Multiple canonical tags are ranked worse than the absence of that tag. Consider this fact for further ranking of the site in search results.
How to fix the issue?
Usually, crawlers define this problem as minor or requiring attention. It means that if the error does not affect the site’s position now, it may negatively affect it in the future.
To solve potential issues with multiple canonical tags at once, choose one way to define canonical tags for your syntax.
- Make sure that for all page templates, the correct canonical address is assigned only once.
- Ask the developer how to determine which ones are easier to manage for each specific website.
Remember that search engines can mark duplicate content as irrelevant, and it can cause some problems.