"Switch" was written by Azalea, Anton Hård af Segerstad, Akil King, Christopher Martin, Georgia Ku, Kyle Owens and Maurice "Verse" Simmonds. It was produced by The Family and Eric Weaver. "Switch" is a pop song, having a "tropical vibe and Latin flavor" as described by Azalea herself. Its instrumentation consists in bass, plucky strings, bongos, and hand claps. As claimed by Azalea, "I wanted to make a song that could be fun to dance to, but the lyrics when you really listen to them are very powerful." Lyrically, the song talks about "looking good and being fierce" and was also described by Azalea as about "a woman being in control of what I want to do and when I want to go and when I want to stop." Lindsey India of XLL added that its lyrics find Azalea "boosting her confidence no matter what the haters might have to say." During the chorus, the sexual lyrics "likens her moves to a traffic light that shifts from red to yellow to green," as they sing: "Red light, yellow light, green light, Switch!/This is about the time you recognize I’m that bitch." In its bridge, as noted by Entertainment Weekly Joey Nolfi, "Azalea seemingly references her separation from former fiancé Nick Young, rapping, 'He don’t love you, that ring ain’t big enough.'" She also raps about "boasting about going topless, along with having a top-tier booty that 'deserves an applause.'"
