Justice first produced tracks together for Musclorvision's Hits Up To You, a concept compilation where tracks were meant to sound like they were meant for the Eurovision song contest.The compilation included two of their songs, and a track by Gaspard's alter-ego Microloisir. Justice first came to prominence through their 2003 remix of Simian's track "Never Be Alone," created for a Paris college radio station's remix contest. The remix resulted in the group being signed to Ed Banger (who released it) and became a hit in clubs and on the internet. The song was re-released in 2004 on DJ Hell's International DeeJay Gigolo Records and eventually given a commercial release in the UK in the summer of 2006, under the title "We Are Your Friends," on Ten Records, a sub-label of Virgin Records.

After the original release of "Never Be Alone", Justice worked on remixes for a number of French groups (Vicarious Bliss, Scenario Rock, Gambit) as well as for larger mainstream acts such as Britney Spears,N*E*R*D, Fatboy Slimand Daft Punk. Justice's first solo single, "Waters of Nazareth", was released on Ed Banger Records in September 2005 and was championed by DJs such as Erol Alkan, Tiga, 2 Many DJ's and Ivan Smagghe. The track was re-released in 2006 with additional remixes. The duo's prolific remix work continued, as they turned in mixes for Franz Ferdinand, Mystery Jets, Soulwax and Mr. Oizo.

Justice won the award for Best Video at the MTV Europe Music Awards 2006, for Justice vs. Simian - "We Are Your Friends". Augé and de Rosnay were not present at the ceremony, and the award was accepted by label art director "So Me" and video director Jérémie Rozan. So Me was famously interrupted mid-speech by rapper Kanye West, who went onto the stage arguing that he should have won the award instead.

Their debut album, titled †, was released on Ed Banger Records on 11 June 2007. The album was released in the United States on Downtown/Ed Banger. The album was preceded by the D.A.N.C.E. EP, released on 28 May 2007, which featured the tracks "Phantom" and their own remix of "D.A.N.C.E." titled "B.E.A.T". "D.A.N.C.E." was nominated for "Video of the Year at the 2007 MTV Video Music Awards. On the first of November Justice received the "Video Star" award at the European Music Awards in Munich and also picked up the best French act of the year. Justice was chosen to do a mix for the Fabriclive series in 2008, but Fabric rejected it. Xavier de Rosnay said that, "[t]hey weren't ready for something like this." Now titled "Justice Xmas Mix," the mix is available on the web.Justice's second submission to Fabric will be released as Fabriclive 40 in June 2008.

Justice at Fabric with the huge lighted cross they typically perform alongside

Justice appeared as a Live PA at the 2007 Coachella festival, the Fuji Rock Festival in Niigata, Japan, the Hultsfred Festival in Hultsfred, Sweden, the Oxegen festival in Kildare, Ireland, the Vieilles Charrues Festival in Carhaix, France, the Roskilde Festival in Roskilde, Denmark, Pukkelpop, in the "I LOVE TECHNO" festival in Ghent - Belgium. Dour Festival in Belgium and the Lowlands festival in The Netherlands, also at Tennents Vital in the Radio One TentBelfast and at the Phoenix Park Marquee in Dublin. Justice's performance at Coachella in 2007 was their first ever live music performance per se. The band's performances before Coachella had seen them DJ using either turntables or CD mixers.

Justice was nominated for Best Dance Recording (for D.A.N.C.E.) and Best Electronic/Dance Album (for †) at the 50th Grammy Awards.

The video clip for "Stress" was boycotted by several TV-stations for being "racist", so the band dumped the video on YouTube where it was seen by 14,000 people within 24 hours after having been posted on 1 May 2008. The video soon garnered much attention in the French and international press. The music video features a group of young men, a number of whom are black, committing acts of vandalism, battery, and destruction of property while wearing matching jackets with the album cover art on the back.

On 1 June 2008, the Sun announced that Justice was chosen by Anthony Kiedis of the Red Hot Chili Peppers to produce the band's follow up to Stadium Arcadium , but this was quickly corrected by Ed Banger manager Pedro Winter as Anthony Kiedis had only stated he was a fan of Justice, not preparing for a collaboration.

 Musical style

Justice is known for their blend of rock music and Electro house.^{[citation needed]} Their music uses a heavy amount of synthesizers, often focusing on the bass sounds. They also use vocals for some of their songs, almost using the them as instruments of their own. Their music also seems to use a heavy amount of syncopation in the various beats for their songs. Their music has also been known to use keyboards and bass guitars and mixers on numerous occasions. Additionally Justice uses samples of certain songs to add to the effect such as their song TTHHEE PPAARRTTYY.

Equipment used by Justice in their productions include an Apogee Ensemble Recording Interface, the Power Mac G5, GarageBand software, and Cubase SX. Their Live setup includes a JazzMutant Lemur Input Device as their main instrument, plugged to Ableton Live. They have also been seen using Pioneer's CDJ-1000MK2 turntable and Korg's microKONTROL midi controller live