York and the band's vocalist, Hayley Williams, wrote the song based on her experience of relocating and the latter's subsequent attitude.

Internationally, the song garnered moderate commercial outcomes, reaching the top 40 of Australian, Canadian, and Venezuelan charts.

[1] "Ain't It Fun" was performed on television several times, including on The Voice, Late Night with Seth Meyers, and American Idol.

The first song completed in Los Angeles for Paramore, "Ain't It Fun" was produced by musician Justin Meldal-Johnsen.

Development for the song started in a hotel room, where Taylor York created an audio loop with his keyboard, which Williams likened to works by Siouxsie and the Banshees and Paula Abdul.

Six months later, they recorded with a gospel choir composed of six individuals: Brandon Hampton, Joslyn James, Katherine and Sean Dancy, Talitha Manor and Yolanda Harris-Dancy.

[5] Jeremy Davis—the band's bassist—expounded on what they felt before releasing the song, "After we started writing weird stuff like 'Ain't It Fun', we got nervous.

York considered that the decision to bring a gospel choir would have been difficult to approve if the original lineup of the band had remained.

[4] Written in the key of E major, "Ain't It Fun" paces at a moderate tempo of 104 beats per minute.

[5][7][8] An editor of the Corvallis Gazette-Times described its melody as "cheery" and "propulsive",[9] while Sean Adams from Drowned in Sound called it "infectious".

The former also compared it to the works of Incubus, while Nicholson stated that it "sounds as if Alexander O'Neal has just discovered Refused's back catalogue".

Club, Annie Zaleski described the song as a mixture of rhythm and blues and pop;[12] Jon Dolan of Rolling Stone characterized it as "soul-powered".

[13] Cameron Adams from News.com.au described it as a funk rock song, while Scott Heisel from Alternative Press classified it as a "blast of new jack swing".

[19]The track's lyrics, structured in verse–chorus form and written in second person narrative,[7] predominantly feature a sarcastic tone.

"[3] musicOMH's Thomas Ingham interpreted its lyrics as focusing on a "serious 'all alone in the world'" theme,[22] while Corvallis Gazette-Times's journalist called them "blunt" and wrote that they discuss "growing up".

[24] In the following month, it was announced that Paramore would participate in the 2014 Record Store Day with the release of a 12-inch single for "Ain't It Fun".

[31][32][33] Jason Lipshutz of Billboard commented, "Williams kept conjuring the refrain [of "Ain't It Fun"], appearing as if she never wanted the moment to end.

Finalist Jena Irene, who preceded Paramore with a live cover of the band's single "Decode", sang the second verse of "Ain't It Fun" alone.

[38] The band hosted a concert on Good Morning America, on June 13, 2014, in which they performed "Ain't It Fun" as well.

Writing for Alternative Press, Scott Heisel felt the song was one of the "moments of diversity that really make Paramore shine".

[41] Jon Dolan from Rolling Stone commented that, on "Ain't It Fun", Williams transitions to a new musical genre on Paramore with an "I-will-survive warrior priestess" attitude.

[13] Kyle Anderson of Entertainment Weekly, Brian Mansfield from the USA Today newspaper and Consequence of Sound's Amanda Koellner selected "Ain't It Fun" as a standout from the album.

[45] Writing for Drowned in Sound, Sean Adams joked that he would eat his modem if the song did not top "all the major charts worldwide", receive a Grammy Award, and amass a high number of views on YouTube.

[10] In contrast, Thomas Ingham of musicOMH criticized its lyrics, deeming it inferior to the track's composition;[22] The Observer's Phil Mongredien wrote that the song's gospel influences did it "no favours".

[51] "Ain't It Fun" debuted at number 96 on the US Billboard Hot 100 chart issue dated March 15, 2014.

She began by brainstorming ideas for the visual, and she talked to Alexandra Young and the video's editor Winston Case, who suggested her the concept of breaking world records.

Peer selected 30 records for the band to break, nonetheless, they reduced the number due to the short length of the video shoot.

The camera shifts to a room where the group attempts to catch flying feathers; Davis breaks the record of catching the most (18) feathers in 30 s. The next scene shows the group wearing eye goggles, in a room with white walls, destroying vinyl records in several ways—such as ripping them, stepping on them or punching them.

He wrote, "That clip was a revelation, the beginning of a bold new chapter for the band, and [the video for "Ain't It Fun"] keeps that winning streak alive."

[75] Fuse's Nicole James surmised that the world records were "adorable", while Steff Yotka of Nylon deemed them "crazy, funny, weird" and concluded that they "make for a truly excellent viewing experience".