How do you say good night sleep well in French?

There are a few ways to say "good night sleep well" in French, depending on the level of formality and closeness you have with the person:

Formal:

* Bonne nuit et dormez bien. (This is the most common and polite way to say it.)

Informal:

* Bonne nuit, fais de beaux rêves! (Good night, have sweet dreams!)

* Dors bien! (Sleep well!)

* Passe une bonne nuit! (Have a good night!)

You can also combine some of these phrases for a more personalized greeting, like:

* Bonne nuit, fais de beaux rêves et dors bien. (Good night, have sweet dreams and sleep well.)

* Passe une bonne nuit et dors bien! (Have a good night and sleep well!)