Backing Vocals – Cathy DennisDrums [Live Drums] – Steven WolfDrums, Programmed By – Benny Blanco (3), Dr. LukeEngineer – Aniela Gottwald*, Emily Wright, Mike Caffrey, Nick Banns, Sam Holland, Tina KennedyEngineer [Assistant] – TIm RobertsEngineer [Engineer For Mix] – John HanesGuitar, Bass – Dr. LukeMixed By – Serban GheneaProducer – Dr. LukeProducer [Additional Drums Production] – Mike CaffreyProducer [Additional] – Benny Blanco (3)Producer [Production Coordinator] – Gary "G" Silver*Written-By – Cathy Dennis, Katy Perry, Lukasz Gottwald, Max Martin

Mixed By – Joe ZookProducer – Greg Wells, Katy PerryRecorded By, Instruments [All] – Greg WellsWritten-By – Andreas Carlsson, Desmond Child, Katy Perry

Drums – Darren DoddKeyboards, Programmed By – Dan ChaseMixed By – Joe ZookProducer, Performer [All Other Instruments] – Butch WalkerRecorded By – Paul Hager*Written-By – Katy Perry

Mixed By, Producer, Performer [All Other Instruments] – Greg WellsRecorded By – Luke TozourWritten-By – Katy Perry

Arranged By [Horns] – Jerry HeyHorns – Bill Reichenbach (2), Dan Higgins, Gary Grant, Jerry HeyMixed By – Joe ZookProducer, Piano, Guitar, Bass, Programmed By [Beats] – Greg WellsRecorded By – Drew PearsonWhistling – Katy PerryWritten-By – Greg Wells, Katy Perry

Bass – Dr. LukeDrums, Programmed By – Benny Blanco (3), Dr. LukeEngineer – Emily Wright, Nick Banns, Sam Holland, Tatiana Gottwald, Tina KennedyEngineer [Assisted By] – Tim RobertsEngineer [Mix Engineer] – John HanesGuitar – Dr. Luke, Max MartinMixed By – Serban GheneaProducer – Dr. LukeProducer [Additional] – Benny Blanco (3)Producer [Production Coordinator] – Gary "G" Silver*Written-By – Katy Perry, Lukasz Gottwald, Max Martin

Guitar – Dave Katz, Sean GouldMixed By – Joe ZookProducer – S*A*M*, SluggoProgrammed By – Dave Katz, Sam HollanderRecorded By – Sean GouldWritten-By – Dave Katz, Katy Perry, Sam Hollander

Drums – Josh Freeze*Written-By – Katy Perry, Ted Bruner

Bass – Paul BushnellDrums – Josh Freeze*Guitar – Dave Levita*, Scott CutlerMixed By – Joe ZookProducer – Anne Preven, Scott CutlerRecorded By – Doug BoehmWritten-By – Anne Preven, Katy Perry, Scott Cutler

Guitar, Instruments [All Other] – Dave Stewart*Mixed By – Joe ZookOther [Production Coordinator] – Stephanie KubiakPiano – Katy PerryProducer – Dave Stewart*Programmed By – Ned DouglasProgrammed By [Additional] – Jeff BovaRecorded By – Bill Malina, Ned DouglasWritten-By – Dave Stewart*, Katy Perry

Mixed By – Joe ZookProducer, Recorded By, Instruments [All Other] – Greg WellsWritten-By – Greg Wells, Katy Perry

Engineer [Drums] – Mike FennelMixed By – Joe ZookProducer – Dr. LukeProducer [Additional] – Benny Blanco (3)Producer, Recorded By, Instruments [All Other] – Ted BrunerRemix – Dr. Luke, Serban Ghenea

Remix – The Knocks

Remix – Anthony Attalla, Christopher Norman

Remix – Morgan Page

Remix – Innerpartysystem

Remix – Bimbo JonesRemix, Producer [Additional], Keyboards – Lee Dagger, Marc JB

Remix – Manhattan CliqueRemix, Producer [Additional], Programmed By – Chris Smith, Philip Larsen

Lyrics By [Additional] – Jean-François PerrierMastered By – Brian Gardner, Chris BellmanPerformer – YelleRemix – GrandMarnier*, Tepr