"Decode" is a song by American rock band Paramore from the soundtrack of the 2008 romantic fantasy film Twilight. It was written by group members Hayley Williams, Josh Farro, and Taylor York.^{[upper-alpha 1]} The song was first made available October 1, 2008 through Twilight author Stephenie Meyer's website.^[1] "Decode" was promoted to American modern rock radio by Fueled by Ramen and impacted on October 21, 2008, serving as the soundtrack's lead single.^[2] It is also included as a bonus track on the international version of Paramore's third studio album, Brand New Eyes (2009).^[3]

"Decode" was an international commercial success, charting in the top 20 of the singles charts in Australia, France, and New Zealand, as well as earning the band their second top 40 hit on the Billboard Hot 100. The song was certified Platinum in the United States on February 16, 2010, selling over 1,000,000 copies. It was awarded the Teen Choice Award for Choice Rock Song, and was also nominated for a Grammy Award in 2010 in the category of Best Song Written for a Motion Picture, Television or Other Visual Media.

Hayley Williams explained how the song's title and lyrics were inspired by the complicated relationship between the book's protagonists:

I chose the title "Decode" because the song is about the building tension, awkwardness, anger and confusion between Bella and Edward. Bella's mind is the only one which Edward can't read and I feel like that's a big part of the first book and one of the obstacles for them to overcome. It's one added tension that makes the story even better.

— Hayley Williams, in a statement posted by Stephenie Meyer.^[4]

"Decode" is an emo inflected alternative and hard rock song written by Hayley Williams, Josh Farro, and Taylor York specifically for the Twilight film.^[5][6][7] It, along with "I Caught Myself", was recorded in September 2008 in Nashville, Tennessee.^[4] According to the digital sheet music published by Alfred Publishing Co. Inc., "Decode" was composed in the key of B flat minor and set in common time to a "moderately slow" tempo of 84 BPM.^[8] The song features a vocal range of one octave, seven notes, and one semi-tone – from the note of G₃ to the note of F₅ – and follows a chord progression of F_maj7 — Am/D — Am — Em.^[8][9]

The song opens with a four bar musical interlude before Williams begins singing.^[8] The song's lyrics speak to confusion regarding one's emotions and a growing sense of uncertainty. "How can I decide what's right when you're clouding up my mind?" she demands in the opening line, while in the chorus she asks, "How did we get here, when I used to know you so well?" According to Heather Phares of AllMusic, "Decode" expounds "Bella Swan's supernatural love triangle angst."^[7]

Alexandra Cahill of Billboard gave the song a positive review, writing, "vocalist Hayley Williams captures the tension and urgency between Edward and Bella with an impassioned, yet restrained performance". Cahill also stated, "expertly crafted follow-up Decode promises to stake a claim at modern rock and top 40 radio".^[10] Leah Greenblatt of Entertainment Weekly said that "Decode" took a step away from Paramore's "bouncier punk-pop sound for a more sprawling, Evanescence-like romanticism".^[11] Heather Phares of AllMusic complimented Williams's "crystalline vocals" on the track, but conceded that it failed to "match the best moments from the band's albums."^[7]

Variety ranked it as one of the best emo songs of all time in 2022.^[12]

The official music video for "Decode" was shot in mid-October 2008 and was directed by Shane Drake.^[1][42] A teaser clip was presented by MTV on October 28, 2008 as part of the network's "Twilight Tuesday" promotion.^[43] The video premiered in full through MTV and its subsidiaries on November 3, 2008 one day ahead of the release of the soundtrack on which the song is featured.^[44] From December 11 to December 18, 2008, the music video and the film trailer were shown in the North American theater of PlayStation Home. The music video is included as a bonus feature with an introduction by the film's director, Catherine Hardwicke, on the DVD/Blu-ray release of Twilight.^[45]

The video features the band members walking and performing in the woods in Nashville, Tennessee (purporting to be Forks, Washington). While they play, there are also scenes of the band acting as tracker vampires searching through the woods. Clips of the Twilight film, primarily those used in the trailer, are also featured throughout the video.^[44]

As of May 2022, the song has 400 million views on YouTube.

Joy Electric released a version of "Decode" on their 2009 cover album Favorites at Play.^[50] The song was performed on American Idol by season 11 finalist Colton Dixon during the top 24 week and by season 13 finalist Jena Irene during the top 11 week, the latter of which was a "Songs from the Cinema" theme.^[51][52]

Paramore has included the song in their setlist for their 2009–2012 Brand New Eyes World Tour and their 2014 Parahoy! event aboard the cruise ship Norwegian Pearl.^[53][54]