Informal:
* Tchau: This is the most common and informal way to say bye.
* Falou: This literally means "spoke" but is used as a casual way to say goodbye.
* Até: This means "until" and is followed by something like "até amanhã" (until tomorrow), "até mais" (until later), or "até logo" (see you soon).
Formal:
* Adeus: This is the most formal way to say goodbye.
* Até breve: This means "see you soon" and is a more formal way to say goodbye.
* Com licença: This literally means "with permission" and is used to excuse yourself from a situation.
Other options:
* Beijos: This means "kisses" and is used as a very informal way to say goodbye, especially among friends.
* Abraço: This means "hug" and is used as a friendly way to say goodbye.
The best way to say goodbye depends on the situation and your relationship with the person you are talking to.