Rachel would be your worst nightmare as a friend on Facebook, regularly changing her relationship status to “it’s complicated” — it’s not; her and Ross have just had a small argument — and humblebragging constantly.
Joey would be a full-time Tinder player, although his charm wouldn’t come across through online messaging. He’d eventually delete the app after regularly stumbling across people he’s dated in the real world.
The quintessential Pinterest user, Monica would spend her evenings obsessively organising her many created pinboards and occasionally criticising the boards of others.
Ross would hate all social media but still have a LinkedIn profile because apparently “that doesn’t count”.
An uploaded video of “Smelly Cat” on YouTube would go viral, although not as much as the Auto-Tuned version, which would make Phoebe internet famous. She’d continue posting videos and gain a small but devoted fandom on the site.
Chandler would almost definitely have a Twitter account, where he’d be tweeting terrible, but very occasionally OK-ish puns to a decent follower count.
Gunther made one post on Google+ in 2011. He still regularly checks to see if anyone’s responded to it yet.