I only say this because of mods and alot of them are about herobrine so... Yeah he technicaly does exist. If any other facts were asked then the answer would be no but because of clever modders actions, herobrine is real. But he is not notche's brother that's just an april fool.
Herobrine does not exist. He is just a Minecraft Myth, and all the videos of people seeing him are not true. And so are the screenshots . There is also NO way of spawning Herobrine in . As I said, all the videos of Herobrine existing are NOT true .
The notch said:
The Herobrine stuff is awesome and kind of scary at the same time. It really shows how little control a content producer has over the content.
" I've publicly told people there's never been any such thing as Herobrine, and that I don't have any dead brothers, and that letting too many animals die in lava is a fool proof way to summon him but that you don't need to be afraid of him. He only means well, he's looking out for you, trying to warn you of the dangers you can't see. There certainly are NO physical manifestations of Herobrine that will sneak out of your computer if you leave Minecraft running at night, looming over you as you sleep with his pale eyes inches away from your face, as he tries to shout at you to wake up. Sometimes you wake up with a jolt, and he's gone, and all that lingers is the memory and faint echo of his wordless screaming. Of course it was just a dream. There's no way a morally dubious ghost with a god complex could at any point decide to haunt the children who play my game "for their own good", as there is NO SUCH THING. Etc etc."
Cited from Notch's posting at-