Is herobrine real?

To put it simply.... No. Herobrine is really only around nowadays as clickbait for youtubers wanting to make money off hundreds of little kids. It used to be a running joke in the update log that it always said Removed Herobrine but ever since we got the new launcher, that's stopped.

The myth of Herobrine: no - He isn't a ghost in the code.
However! It has occured quite a few times that a player with the name of Herobrine, has joined various Realms which he had been invited to. I dont recall how long ago it was, but I remember a post here on the PMC forums where someone actually encountered the dude who had access to the Herobrine account, where he told them that he got access through using some... Not so legal means :')

So the myth is fake, but the player is real :)