A disco-pop, dance-pop, and EDM track, the song was written by Jenna Andrews, RM, Alex Bilowitz, Sebastian Garcia, Robert Grimaldi, Stephen Kirk, and Ron Perry, with production handled by the last three.

[3][4] Rolling Stone described it as "a pure, swaggering dance-pop celebration in the retro vein of Bruno Mars, with layers of Jam and Lewis-style synths", and RM told the outlet that the song "[is] very energetic" and "very summery".

Suga also tried writing for the song, as he had actively been studying English during the year prior, but the language barrier was still a problem, so his suggestions were "immediately dropped.

[14] Lyrically, like "Dynamite", "Butter" has "no heavy message";[5] Jimin noted that there was no profound meaning behind the track and that the goal was for it to be "easy to listen to".

[16] Korean news media later reported that the lyrics to "Butter" "cutely confess a sweet, romantic love", and had "BTS' smooth-like-butter unrivalled charms melted into the song".

[20] On April 26, the single's title and release date were announced in an hour-long YouTube live stream of an animated stick of butter melting.

[22] Concept photos and video teasers for the song, set to be BTS's second English-language single,[3][4] were shared through the band's official social media in the weeks following.

[24] BTS appeared as the first guests on Big Hit's new exclusive Melon Station radio series, BigHit Music Record, on May 21 to introduce "Butter" and participate in a Q&A with fans.

[31] Writing for NME, Rhian Daly praised "Butter" as "a clean and crisp piece of dance pop that's undeniably cool without sacrificing immediacy or memorable hooks" and felt it was a strong, early contender for song of the summer.

It's a big, slick party song that targets pleasure receptors with mathematical precision" and compared it to Daft Punk's Random Access Memories and works by Bruno Mars.

[34] Zach Seemayer of Entertainment Tonight felt that the song's hook, with its "truly catchy beat" and "fun" opening lyrics, "has the hallmarks of a real hit with legitimate song-of-the-summer potential".

[36] Consequence's Mary Siroky named "Butter" the song of the summer and "a synth-drenched, swaggering track sitting comfortably on an addictive bassline".

[16] The short monochromatic clip showed BTS dressed in "disco-inspired" suits "with shoulder pads, glitter, and satin galore",[51] standing motionless in a line,[16] while "a groovy percussion ensemble played in the background".

[2] Fifteen minutes prior to the music video's premiere, BTS appeared in a special countdown stream on the Hybe YouTube channel to discuss the song while making buttered sandwiches[50]—it was simultaneously released with the single at midnight EST.

Interspersed are "striking black and white shots" of the band dressed in "slick suits" dancing together to a "strong percussion ensemble"—first heard in the May 18 teaser—and standing in a lineup while holding mugshot placards with their names on it.

[50][7][35] The video then "transitions into [a] rich and vibrant color palette"[35] as the band perform "power-packed", "nimble dance moves" in several "dazzling locations with soft, full-color lighting...against an array of flamboyant backdrops" such as a gymnasium (while wearing "summery gymwear"),[55] a mock press conference, an elevator, and "onstage under pulsating lights" in "black-and-yellow tuxedos".

[14] The video also features a "TikTok-ready, technicolor elevator sequence" in which the individual members freestyle their dance moves, including "putting on imaginary cologne".

[63][64] On June 28, it became the longest running #1 debut for a group in Hot 100 history, breaking the 23-year record held by Aerosmith's "I Don't Want to Miss a Thing" (1998).

[65] Entertainment Tonight's Zach Seemayer wrote that the music video "takes fans on a spectacular journey in both set design, color schemes and outfits".

[67] Dressed in one set of outfits from the original music video, the clip shows the band "at their cheeky best", "cutting loose" and "taking turns at being front and center" while making "goofy, fun faces at the camera and with each other".

[71] In Japan, "Butter" earned its largest opening-day digital sales in the country, with 27,772 downloads,[72] surpassing its predecessor "Film Out", which sold 23,344 copies on its first day.

[82] "Butter" debuted at number one on the Billboard Hot 100 chart issue dated June 5, 2021, giving BTS its fourth number-one in under nine months.

[98] Per the International Federation of the Phonographic Industry's (IFPI) global music report for 2021, published in 2022, "Butter" was the fourth best-selling single of the year across all digital formats, with 1.76 billion streams accumulated worldwide.

In an article published by Billboard in August 2021, the magazine pointed out that the band's fans have "through above-board means" taken advantage of loopholes in chart tabulations to boost the ranks of singles such as "Butter" in the US and help the song top the Hot 100 for multiple weeks.

While the chart performance of singles on the Hot 100 typically depend on streaming and airplay, that of "Butter" was notably driven mostly by sales (the bulk of which came from BTS's webstore, which allows fans to buy multiple copies of a song, unlike iTunes) and by fan-led crowdfunding efforts (including using money collected from fans worldwide on services like PayPal to make purchases that count toward US sales only).

[103][104] BTS performed the song later that night on The Late Show with Stephen Colbert, this time appearing in "a grand ballroom, fitted out with glorious chandeliers and art deco features, and raining with gold glitter".

[105] The band was the first musical act in the lineup for Good Morning America's 2021 Summer Concert Series, appearing on the May 29 episode, where they performed the track as part of a two-song set that also included "Dynamite".

[109] The televised world premiere performance of the remix with Megan Thee Stallion was initially scheduled for the 2021 American Music Awards.

[110][111] The following week, she made a surprise appearance during the second night of the band's four-day concert series at SoFi Stadium and performed the remix together with them for the first time.