I’ll also add another major sign is if you don’t know their irl names. I have close friends who I met over the pandemic who live far away, but we knew each other by name and hear each other’s voices. That’s a big thing. Your Twitter/tumblr mutuals or people you regularly interact with on Reddit/Lemmy are people that terminally online people will think of as friends rather than “no we’ve never met irl but we play d&d together or have a book club over discord”.

The other big thing is whether or not you go to irl events. Just literally being somewhere that’s neither home nor work/school helps so much.