I have a Rails application running on production server. And recently I implemented canonical URL on it as requested by higher order people. After implementing it I checked it some online checkers. This is what they are showing:
Page URL:
https://example.com/search?category_id=metal-processing-and-machine-tool
Canonical URL:
https://example.com/search
Result: CORRECT
Is this right? I am not quite convinced by the online checkers. Could somebody please explain me if this is right or wrong?