John Egbert is the first introduced character in Homestuck, which by some standards also make him the protagonist, although as Homestuck grew, there was at least a half dozen characters that shared this status. The opening panel of Homestuck occurs (both in the story and in the real life) on April 13, 2009, which is John Egbert's 13th birthday. One of the easiest ways to understand Homestuck is a bildrungsroman, and John Egbert's entrance on his first day as a teenager certainly reflects that.
John Egbert is introduced as a seemingly average American 13 year old, living in the quiet suburb of Maple Valley, Washington with his father. He has various hobbies, including liking 1980s movies, magic tricks and computer programming. His three best friends from the internet are Dave Strider, Rose Lalonde and Jade Harley, all of whom are a little older and more colorful than him. John is intelligent but a fairly linear and limited thinker, and one of the first serious moments in Homestuck is when he realizes that something is "missing from his life". This revelation is followed by Homestuck taking a turn first towards magical realism and then towards science fiction, when his friends and him enter a reality-warping game. John Egbert, despite his seemingly innocent nature, becomes their natural leader as they work their way through an increasingly deep mystery. Despite having a juvenile sense of humor and a taste for practical jokes, John Egbert often serves as a straight man between his more colorful friends, as well as at times being an audience surrogate, with his own puzzlement and search for explanations of the story being a stand-in for the audience. He generally has a polite and moral character, although he can be tempermental or rude.
In the system of the world him and his friends enter, he gains the title of Heir of Breath, and his character is often connected with the idea of the wind, either literally or figuratively. He also has blue eyes and wears blue clothing, symbolic of the sky. Despite starting out as the most down-to-earth character, he also represents freedom or liberation, something that is a touchstone of Homestuck's increasingly convoluted narrative and symbolic framework.
Although Homestuck was infamous for providing a branching, self-referential, and convoluted narrative, what some might term post-modern, its main protagnost, John Egbert, is portrayed as being both narratively and morally unambiguous. He serves as an understandable guide and touchstone for the reader through the story.