He is best known for his 2015 single "Faded", which received platinum certifications in over 10 different countries. He is ranked 17th on DJ Mag's Top 100 DJs list of 2017, placing 38 positions higher than the previous year.
Walker is a son of Hilde Omdal Walker, a Norwegian, and Philip Alan Walker, an Englishman By birth, Growing up in the digital era, Walker found an early interest in computers, which later turned into a fascination for programming and graphic design. He initially had no musical background; however, he later taught himself by watching tutorials on YouTube based on music production.
In 2012, Walker was listening to a song by David Whistle (formerly known as DJ Ness), and reached out to the Italian DJ to find out how he produced his music. He started all his music on his laptop with FL Studio. In July 2012, with the help and feedback from his fans online, he began pursuing his music production career and slowly began posting his music to YouTube and Sound Cloud.
Walker released the track "Fade" on 17 August 2014.The track gained attention after its re-release via the record label No Copy right Sounds on 19 November. Walker stated that the creation of the track was inspired by K-391 and Ahrix, whose tracks were also picked up by the record label. The track has over 300 million views on YouTube, 79 million plays on Spotify, and 20 million streams on SoundCloud. It has become the most popular track on the channel, and is widely used by You Tubers in their videos. The tracks "Spectre" and "Force" followed in 2015.
Walker signed with MER Musikk under Sony Music Sweden and his next single, "Faded", was a remastered vocal version of "Fade". The single topped the year-end charts in Austria, Germany, Switzerland and Sweden, iTunes charts in 32 countries, as well as entering top 10 in Spottily Global Chart. The music video on YouTube has over 1.9 billion views and 12 million likes,placing it among the top 10 most liked YouTube videos. It has over 780 million plays on Spotify, and is also one of the Top 10 Most Shazamed tracks of 2016. The single also received official remixes from Tiësto, Dash Berlin and Hardwell.
Walker quit high school in January 2017, On 27 February, Walker made his live performance debut at the Winter X Games in Oslo, where he performed 15 tracks including the song "Faded" together with Iselin Solheim. Walker had produced 30 to 40 songs in total, but "Faded" marks his first single with Sony Music Sweden, and the first to achieve such global success.
The single "Sing Me to Sleep" was released on 3 June, featuring female vocalist Iselin Solheim, the same vocalist in "Faded". The song topped iTunes charts in 7 countries. Its music video on YouTube has over 400 million views, and it also reached 170 million plays on Spotify.
The single "Alone" was released on 1The music video on YouTube has over 610 million views, the track also gained over 210 million plays on Spotify. The song was described as "the final piece of a trilogy consisting of 'Faded', 'Sing Me To Sleep' and 'Alone'" by Gunnar Greeve, Walker's manager and co-writer for the single.