Haim was formed in 2006, in San Fernando Valley, California, after spending their childhood as part of family cover band Rockinhaim.

[7] "Forever" was written by band members Alana, Danielle and Este Haim, who also produced the track along with Ludwig Göransson,[8] a Swedish composer who has helmed the music for the US TV series Community, Happy Endings, New Girl, and The Mandalorian, as well as the film Fruitvale Station.

[11] Musically, "Forever" is a pop rock song,[1] featuring staccato melodies[12] and bear-trap drums snap, which were considered similar to some echo of a Jam & Lewis production under ripples of synths lifted from a Teena Marie or Suzi Quatro record by Spin's Mike Powell.

Matt James of PopMatters described the song as an "all teasing 'stop-start', Prince percussive crunch and 'Wanna Be Startin' Something' shakin' guitar licks.

"[17] Brendan Frank of Beats Per Minute called it "an electrifying R&B wiggle",[18] while Michael Roffman of Consequence of Sound praised "the whimsy of spacey reggae anthem".

[20] Embling of Tiny Mix Tapes shared the same thought, calling them "essentially perfect, every single second engineered within an inch of their lives, to the point where resistance becomes either impossible or unconscionable.

"[22] Larry Fitzmaurice of Pitchfork Media praised the track, writing that it has a "sparkly charm about it, its palm-muted guitars and soaring vocals creating a fizzy effervescence.

"[14] El Hunt of DIY Magazine went on to praise the band for "conjur[ing] glimmering pop foundations on ‘Forever’ that spiral upwards in strange geometric structures, built upon gasping, fragmented delivery and plunking bass.

"[24] Forrest Cardamenis of No Ripcord praised the track, writing an extense article about it, claiming: "Guitars jangle a bit more, as this one is more rock than R&B, and the lovelorn lyrics, for all their cheesiness, are incredibly endearing.

[33] The video for "Forever" features old footage of the sisters as kids on holiday intercut with shots of them riding on their bikes and in the salon, while guys do wheelies on motorcycles.

"[34] Michael Cragg of The Guardian called it "the perfect mix of studied cool, 90s teen drama, and Destiny's Child dance moves.