[2] Madeon, who previously worked with Gaga on her 2013 album Artpop, first recommended other producers who he felt to be a good fit for the song, but ultimately BloodPop invited him directly.

"[3] According to BloodPop, while Gaga was recording "911", she insisted that the studio be near pitch-black and that she wear a wig in order to feel like someone else as she wanted to "relive everything she was talking about in the song with every take".

"[7] In the chorus, Gaga acknowledges her mental illness and her high reliance on the antipsychotic with the line "My biggest enemy is me / pop a 911", with 911 both referring to the emergency phone number and her medications.

[9][10] Vulture, an online blog associated with New York Magazine, opined that "911" captures "the inside of Gaga's brain as if it's a sci-fi construct, where neurons fire and spark chain reactions beyond her control.

[17] The Observer's Emily Mackay highlighted how the pace of the music is in harmony with Gaga's lyrics, writing "the beat jackhammers, driving her up to a Donna Summer trill, then slows to a more comfortable groove as she regains perspective and control".

"[22] Nick Smith of MusicOMH noted similarities to Kylie Minogue's "Speakerphone" (2007),[23] while Slant Magazine's Alexa Camp deemed "911" reminiscent of Gaga's past singles, "LoveGame" (2009) and "G.U.Y."

[24] Similarly, Lindsay Zoladz of The New York Times felt that "911" harkens back to Gaga's earliest hits, and wondered if nostalgia for the late 2000s music "is already a thing".

I remember this moment in the studio so clearly, because she lit up, and without any words I flipped the keyboard around, pulled up the string sound she was envisioning, and she started to play this amazing marcato idea.

[12] It generated several memes, with people editing the transition into various scenes from movies and TV,[25][26] and recreating it with similar sounding songs, most notably with Kylie Minogue's "Can't Get You Out of My Head" (2001).

"[33] Stephen Daw of Billboard ranked the track as the third best from the album, with "deeply satisfying production" and "some ridiculously clever songwriting", while saying that Gaga "is in her element when she is delivering camp.

"[34] Kory Grow from Rolling Stone thought the song "splits the difference between the Buggles and Kraftwerk, filtered through Gaga's kaleidoscope" and noted that "she's at her best... when taking musical risks", like with "911".

[35] Tom Johnson from The Line of Best Fit also found it an album highlight, saying that along with another track, "Replay", they are both "honest and thoughtful, brilliant dance music.

[19] At Uproxx, Caitlin White said "911" is a standout where Gaga "manages to expertly balance her suffering and self-frustration with the dancefloor freedom that defines the album".

"[38] Writing for PopMatters, Evan Sawdey thought that even though "Gaga is still hiding behind vocoders and numerous filtered vocal effects", the song is one of the best moments of the album as her "real life and experiences are seeping through the gaps in the 4/4 rhythm chains".

[39] According to Slant Magazine's Sal Cinquemani, Gaga's "distorted vocals" and the "euphoric swoon of the track's pre-chorus" create an "effective contrast".

[41] Mark Richardson from The Wall Street Journal felt that "911" along with another song, "Enigma", "find Lady Gaga deploying the more bombastic style of her earlier hits to lesser effect.

[50] In Italy, the song charted at number 92,[51] and later it was certified Gold by the Federazione Industria Musicale Italiana (FIMI) for selling over 35,000 units.

[53] LG Electronics later included an exclusive edit of the music video, along with commentary by Tarsem Singh, on its FOMO channel which is available on the company's smart TVs.

As the song starts, she enters the mission filled with oddly dressed people, including a man banging his head onto a pillow and a woman resembling Santa Muerte cradling a mummy.

Gaga begins to cry and wail, waking up in the real world, where she is seen lying outside of a cinema, where a big sign advertises an "Armenian Film Festival".

[55] Similarly to The Wizard of Oz (1939), the characters appearing in Gaga's imagination are portrayed by the same people who she saw in reality, the victims and first responders who are at the site of the accident.

[68] Justin Curto from Vulture wrote that "Lady Gaga is back to being her fully indecipherable self in her new music video [...] with an instantly iconic cast of characters and a twist that demands hours of rewatching and theorizing.

[73] Pitchfork's Eric Torres ranked the video as the third best one of September 2020, claiming "all the head-scratching symbology slips away, revealing a twist ending that should probably come with a trigger warning.

[81] Frantic red lights illuminated the stage,[82] while Gaga was singing the song in a vinyl dominatrix ensemble, complete with a policewoman cap.

[83][84] In his review for the tour, David Cobbald of The Line of Best Fit highlighted the "notorious" transition from "Chromatica II" to "911", praising the dancers for the choreography which was "executed with precision and togetherness".

[93] Neil Z. Yeung of AllMusic called the remix one of the highlights of Dawn of Chromatica, saying that "Charli XCX and A.G. Cook revive '911' as a pulsing digital epic".

[94] Pitchfork's Jamieson Cox praised the "crystalline hyperpop" remix and its "stunning" final verse and outro, dubbing it "some of Charli's finest work since Pop 2," her mixtape from 2017.

[95] Alexa Camp of Slant Magazine thought that XCX "injects some much-needed expressiveness" in the song, while Cook "drags [it] from the late aughts into something approaching the future.

[97] Writing for Gigwise, Alex Rigotti called it the third best track on the record, which "transforms the rigid, robotic original into something way more chaotic, but tense", delivering "high drama" while "sounding utterly transcendental".

[98] Joey Nolfi of Entertainment Weekly thought that XCX reimagined the song "into something that suits her own brand while bringing out new layers in Gaga's raw lyrics.