Formal:
* Bis später! (This is the most common and straightforward translation)
* Auf Wiedersehen! (This literally means "goodbye," but can be used for "see you later" in more formal situations)
Informal:
* Bis dann! (More casual than "Bis später!")
* Ciao! (Borrowed from Italian, commonly used among young people)
* Bis bald! (Means "see you soon," but can be used for "see you later" in informal situations)
Other options:
* Mach's gut! (Literally means "do well," but can be used as a casual farewell)
* Bis zum nächsten Mal! (Means "until next time")
The best translation will depend on the specific situation and your relationship with the person you are speaking to.