Formal:
* Hasta luego: This is a more formal way of saying "see you later" and implies a shorter period of time than "hasta pronto."
* Nos vemos pronto: This means "we'll see each other soon" and is a more friendly and personal way of saying goodbye.
* Que tenga un buen día/tarde/noche: This means "have a good day/afternoon/night" and is a polite way to say goodbye.
* Adiós: This is a general goodbye that can be used in any situation.
Informal:
* Ciao: This is a casual and informal way of saying goodbye, often used among friends.
* Nos vemos: This means "see you" and is a more casual way of saying "hasta pronto."
* Adiosito: This is a cute and informal way to say goodbye, meaning "little goodbye."
* Te veo luego: This means "see you later" and is a more casual way of saying "hasta pronto."
Other options:
* Keep in touch.
* Talk soon.
* Let's get together soon.
* I'll see you around.
Ultimately, the best way to say "hasta pronto" will depend on the specific context and your relationship with the person you are saying goodbye to.