"Stressed Out" is a mid-tempo alternative and rap rock song that runs for a duration of three minutes and twenty-two seconds. According to the sheet music published at Musicnotes. com by Alfred Music, the song is written in the time signature of common time, with a moderate tempo of 85 beats per minute. It is composed in the key of A minor, while Tyler Joseph's vocal range spans from the low-note of E3 to the high-note of A4. The song follows in the chord progression of F–Dm–Am in the verses and pre-chorus, and Am–G–C–E during the refrain and bridge.