"Strangers" has been described by critics as pop-punk, alternative rock, pop rock, hard rock, and an emo song. The song was written by the band's lead vocalist Oliver Sykes, keyboardist Jordan Fish, guitarist Lee Malia, Caroline Ailin and BloodPop, while it was produced by Zakk Cervini, BloodPop and Evil Twin. The song touches on the different kinds of trauma in its lyrical content and how Sykes wanted to use that to bring people with mental health problems together. Sykes explained his thought process on how the song came together:
