Is it bad to say I work too hard as a weakness?

In most interviews, yes. The sentence describes effort rather than a cost, so it reads as a strength wearing a weakness costume, and it leaves the interviewer with nothing to verify. It also breaks under the first follow-up. If overwork is genuinely your problem, say what it cost: I answer messages on Sunday and start Monday tired, so I now leave my laptop at the office on Fridays. That version names a consequence and a rule; I work too hard names neither.

The Interview Weakness Question in English: Three Safe Answers and the Ones That Sink You →