Written by Jessie J, The Invisible Men, Ali Tennant, David Guetta, Giorgio Tuinfort, Frédéric Riesterer and produced by Guetta. This song features the vocals of English singer-songwriter Jessie J. Guetta explained to UK newspaper The Sun why it was a stressful time trying to get this track finished. Said the French DJ: "We didn't meet in the studio on this track so it was a case of spending a lot of time on my laptop and emailing each other. The album was finished then I got word from Jessie about this collaboration so I called my label and said, 'Stop everything. The album can't go without this track.' But I was in Ibiza, where the internet is bad, so I had to go to the airport lounge to work. I would sit all day in the lounge with my headphones on, looking like a homeless person, finishing the vocal mix on my laptop. Then Jessie would come back asking, 'Can you just change this little thing?' so I'd go home then be back in the airport lounge for another few hours."
Scott Shetler of PopCrush said: "Guetta wisely avoids the synth loops on the mid-tempo track 'Repeat' and instead lets Jessie J show off her voice: "I wanna know was I the one, or just the chick on the side? / I gave it all, broke it down my walls, don't you dare say I didn't try." An infectious hook makes 'Repeat' one of the most fun-sounding breakup songs we can remember." Digital Spy's Robert Copsey gave a review: "A combination of a chill melody, emotional vocals, and a more progressive tune make this a first for Guetta. "Repeat" reminds us a little of "When Love Takes Over", not as big room but same sort of transition. While the vocals of Jessie J are pleasant, they don't lead us to believe that this will be any sort of genre transcending track."