Formal:
* خداحافظ (khodahafez) - This is the most common and formal way to say goodbye. It literally means "God be with you."
* بدرود (bedrood) - This is a more poetic and literary way to say goodbye, meaning "farewell."
Informal:
* خدانگهدار (khodanegedar) - This is a more informal and friendly way to say goodbye, meaning "God keep you."
* خداحافظی (khodahafezi) - This is another informal way to say goodbye, literally meaning "goodbye."
* تا بعد (ta ba'd) - This means "until later" and is very common in informal situations.
* فعلا (fe'la) - This means "for now" and is another informal option.
You can also use a combination of these phrases, such as "خداحافظ، تا بعد" (khodahafez, ta ba'd) which means "goodbye, until later."
The best way to choose the appropriate greeting depends on the context and your relationship with the person you are saying goodbye to.