Is Hamlet insane or sane?

The answer depends partly on how you define insanity and at what juncture of the play you're making your judgments.

Sane

Explanation:

Hamlet was sane because any words or actions of insanity could lead a person to think he was insane, although he could have used them to cover up the fact of his personality change due to the death of a family member. Hamlet was also very smart and rational. He was also determined and followed through all his well thought plans. His insanity was believed because of his personality change. However the change was because of recent family tragedy.