Laptop or desktop? Make/model?
Wired or wireless mouse? If wireless, have you tried replacement batteries? Make/model? Current scroll rate setting?
Device OS? Edition and version.
Judders on all web pages or just one? If just one, what's the URL?
When did behaviour start, what changed and what have you tried so far?
All in all, your query is unanswerable at present with the current paucity of information.
(I almost didn't bother replying. You need to help us in order for us to help you... we're not clairvoyant.)