If one does nothing, what happens to facebook chats?

They are saved. If you exit out of facebook, then sign back on, any opened chats are saved!

They aren’t always saved, I find when I log back in the chat tabs are still there, but there is usually no text. I’m pretty sure they’re gone forever. I do a lot of copy/pasting.

They’re saved for a short time. Like, if your internet flicks off and you sign back in two minutes later or so then you’ll still have it. But if you log out for the night, it usually won’t be there the next day.

I wish FB had a way to save chats.