Translation guide
How to say 'good night' in Japanese, depending on the situation and relationship.
Wishing someone a good night's sleep or saying goodbye at night.
Polite and standard way to say 'good night'. Used with people you are not close to, or in formal situations.
Good night, teacher.
Casual form of 'good night'. Used with family, close friends, or people of equal or lower status.
Good night, see you tomorrow.
Saying goodbye when parting at night, not necessarily going to sleep.
Use おやすみなさい in formal situations or with superiors. Use おやすみ with close friends, family, or children. The difference is similar to 'good night' vs 'nighty night' in English.
Unlike 'good night', おやすみなさい is only used when parting or going to bed. It is not used as a greeting when meeting someone at night. For that, use こんばんは (good evening).
じゃあ、おやすみ。
Well then, good night.