Google’s John Mueller said on Twitter that having two canonical tags with different URLs on the same page is the same as having an undefined canonical tags:
AFAIK it's just undefined (so if you want it to do something, write it right). Also, rel-canonical isn't a directive, it's just one of the signals that flows into the canonicalization process.
— ? John ? (@JohnMu) November 5, 2020
How to check the canonical tags on your website
Use the website audit tool in SEOprofiler to check the canonical tags on your web pages. The website audit tool checks many more things and it helps you to ensure that your web pages get the best rankings:
