You can explicitly tell search engines the canonical URL, but they can also group multiple URLs together on their own.
If Google finds that different paths (like /products/phone and /phone) lead to the same content, it may automatically bundle them into one group and pick a representative on its own — not necessarily the one you want.
Although Google is very good at detecting these issues, its system is so massive that it can't cover every extreme edge case.
The canonical tag is a critical factor in ensuring excellent website performance.
Canonical tags become especially important here.
They tell Google which URL is the original authoritative source and which are duplicates.
Having a large number of duplicate pages — whether under the same domain or different domains — can lead to ranking drops, or even penalties.
If Google finds multiple URLs with identical content, it may lower their rankings in search results, treating them as duplicate content.
This can also happen across domains. If you run two different websites and publish the same content on both, search engines might choose only one to rank — or penalize both by lowering their rankings.
Canonical tags are crucial for SEO performance because they can be used to create different URLs, and users or marketing tools can also create them.
Let's say you're running a marketing campaign on Google, and Google decides to add some UTM parameters. This new unique URL might be indexed by Googlebot, so you need to ensure your canonical tags are still displayed to maintain consistency for duplicate pages.
