Klitzner started his career in online videos on CollegeHumor. Every week he and his college friends would create a video in a series they called the Weekly Fix. Some of the videos Sean originally created for his weekly fix were edited and reposted to his YouTube Channel. These videos include "Wilbur Lister", "Gladiator Adventures" and "Speed Marries Iron".
YouTube
On February 19, 2006, Klitzner created a YouTube account. It was only a few years later that he was uploading regular content. On the December 20, 2010, Klitzner uploaded The Fixify, his first regular YouTube show in which he would talk about pop culture. One of Klitzner's videos featuring himself debunking a scene of the eleventh episode of the fourth season of Jersey Shore was featured on a NowPublic article. In 2012, fans tweeted at Klitzner to tell him to join YouTube's Next Up Comic Contest. He did, and he was chosen as one of the 16 winners and was given the prize of $5,000 worth of video equipment, $10,000 worth of channel promotion and 3 months of educational workshops being mentored by professionals from CollegeHumor and GloZell. In September 2012, Klitzner appeared as Mitt Romney on What's Trendings "Obama Style", a parody of the viral video "Gangnam Style". In October 2012, Klitzner collaborated with Thomas Ridgewell on an episode of Klitzner's A Killer Song!. During the same month, Klitzner appeared as a guest host on SourceFed.
Other channels
On December 9, 2011, Klitzner uploaded his first vlog on the YouTube channelSeanKlitzner2. In these vlogs, Klitzner often has motivational "one on one" sessions with his audience; he has addressed and helped fans deal with depression, self hatred, and low self-esteem. In early 2011, Klitzner created a YouTube channel named MrDreamtastic. Klitzner would leave his camera by the side of his bed each night, and in the morning, after a dream he would turn on his camera and present his dream to the camera. After about 30 episodes of his dream vlogs, Sean decided he was unable to maintain long and interesting dreams for the vlogs. This was due to some pesky chickens that lived nearby who kept making noises and waking him up in the night. So Sean stopped creating dream vlogs. Then in 2012 Sean started having dreams suitable for making videos again, but instead of uploading more vlogs onto his MrDreamtastic Channel, he decided to delete the Dream Channel and upload each Dream vlog again one by one to his main Channel on a schedule of every other Monday. After all of the Dream vlogs that were originally posted onto the Dream channel are put onto the Main channel, Sean intends to upload new Dreams from 2012 onto his channel. On October 3, 2011, after speaking to Toby Turner who suggested he make a gaming channel, Klitzner uploaded his first gaming video on a channel called "KlitznerGames". Klitzner wanted to have his own style, so he chose to only play "Old School" video games, he chose to dress up as the main character of each game he plays and he sets his camera to record him every time he plays so you can see what costume he is wearing. Also, he can only play 2-dimensional games because Klitzner gets sick if he play 3-dimensional games. In late 2019, Klitzner started hosting a radio show called "The Sean Klitzner Show" that started at 10PM every weekday night on WDBO-FM.
Klitzner is a University of Miami alumnus. At the University of Miami, Klitzner graduated in only three years with a double major in film production and theater.
Television
Klitzner appeared in ABC Family's television seriesSwitched!. In 2005, Klitzner appeared in an episode of Barbershop. In 2010, Klitzner appeared in five episodes of VH1's Undateable television series. In 2011, Klitzner was a cast member of the Disney Channel series PrankStars.
Sean married Noelle Kilegl privately in 2012; the two held a formal ceremony on December 29, 2013. The couple's first child, Brooklyn Violet Klitzner, was born on September 11, 2014. The couple's second daughter, Harlee Rayne Klitzner, was born on April 22, 2017. Klitzner also has 2 stepsons.
