In Canada, the musician worked with Play Digital label, which he helped become one of the most successful online labels on Beatport.com. Deadmay5’s singles were performed by such DJs as Chris Lake, Pete Tong, Nic Fanciulli, Sebastien Leger, and John Acquaviva. Later, Joel created his own labels, Mau5trap and Xfer Records.
In 2007, Deadmou5’s career took a huge step forward when his track “Faxing Berlin” made its way into the hands of a British DJ Pete Tong. At that time, Deamous5 began making digital singles for other artists.
Zimmerman’s pseudonym didn’t appear in a random manner. When he was still young, while changing his computer’s graphics card, the DJ discovered a dead mouse in the computer case. He told that story to his friends, who jokingly called the artist “that dead mouse guy”. Eventually, the nickname was shortened to dead mouse and later stylized as Deadmou5.
The idea to wear a helmet mask, which the DJ called mau5head appeared thanks to the logo for the label. Joel created a logo, which looked like a head of the mouse with large ears. One of Zimmerman’s friend used Photoshop to replace Joel’s head with a logo. The DJ liked the way the photo looked and ordered a custom helmet to wear at concerts.
Deamou5’ first release was "This Is The Hook". He wrote it with Steve Duda. The young men called their group BSOD (Blue Screen Of Death). The release was planned as a joke. The musicians used house beat and combined it with digital voice. They didn’t expect the single to top Beatport chart. Many clubs started trying to book Deadmou5 for private events.
Soon after the release, Steve moved to LA. Joel presented his first solo single "Faxing Berlin" under the new pseudonym Deadmau5. Pete Tong played it on one of his shows on BBC Radio 1.
In 2009, Joel released an LP, For Lack of a Better Name, which featured such popular tracks as "Strobe" and "Ghosts 'n' Stuff". Next year, he presented 4 × 4 = 12 with such singles as "Some Chords", "Sofi Needs a Ladder", and "Human Rights".
The DJ’s sixth album, Album Title Goes Here, came out in September 2012. It came in 6th on Billboard 200 and 2nd on Canadian Albums Chart. The LP featured such popular singles as "Maths", "The Veldt", and "Professional Griefers". The new LP, While(1<2), came out in 2014.
At the end of 2015, there were rumors about Zimmerman leaving the music business. He seemed to be taking a break. The musician even deleted his Facebook and Twitter accounts. Deadmou5 soon announced that he had depression and wanted to come back in a few weeks.
The next single came out in the spring go 2016. It was "Snowcone". The single was featured in the artist’s next album, W:/2016Album/, which came out the same year.
Between 2016 and 2019, the DJ released thee EPs from Mau5ville series. All three albums (Level 1, Level 2, Level 3) were successful.