In English we have a few different ways of saying goodbye.
Goodbye and bye bye are two phrases that English learners use but they are actually not common for native speakers to use. Goodbye is a little cold and bye bye is a kids' phrase!
Let's take a look some better ways!
Here are some informal slang phrases you can use with friends.
Catch you later
Later
So long
Gotta go
See you later/soon/next time
Have a good one!
I'm out/off
Take it easy
Peace out
It was nice/great seeing you
It was nice to meet you (usually used after first meeting)
It was good to catch up