We kind of freaked out when we realized that Justin Bieber started his Kidrauhl YouTube channel eight years ago today: back then, he was so little, entering singing competitions and strumming on his guitar! Now, he's all grown up and looks so different than he used to: but he's not the only one!
Click through the gallery below to see which stars have totally transformed from their YouTube days. Which celeb shocked you the most? Let us know in the comments section below!