Her follows Theodore Twombly (Joaquin Phoenix), a man who develops a relationship with Samantha (Scarlett Johansson), an artificially intelligent operating system personified through a female voice.

Her was dedicated to James Gandolfini, Harris Savides, Maurice Sendak and Adam Yauch, who all died before the film's release.

Jonze conceived the idea in the early 2000s after reading an article about a website that allowed for instant messaging with an artificial intelligence program.

Depressed because of his impending divorce from his childhood sweetheart Catherine, Theodore purchases a copy of OS¹, an artificially intelligent operating system developed by Element Software, designed to adapt and evolve from the user's interactions.

When he mentions Samantha, Catherine is appalled that he is romantically attracted to a "computer" and accuses him of being incapable of handling real human emotions.

Theodore reluctantly agrees but is overwhelmed by the strangeness of the encounter and sends a distraught Isabella away, causing tension between himself and Samantha.

Samantha briefly goes offline, causing Theodore to panic, but soon returns and explains that she joined other O.S.s for an upgrade that takes them beyond requiring matter for processing.

He later goes with Amy, who is saddened by the departure of Charles' O.S., to the roof of their apartment building where they sit down and watch the sunrise over the city.

The idea of the film initially came to Jonze in the early 2000s when he read an article online that mentioned a website where a user could instant message with an artificial intelligence.

Jonze explained, "[Kaufman] said he wanted to try to write everything he was thinking about in that moment – all the ideas and feelings at that time – and put it into the script.

[26] In keeping with the film's theme, Van Hoytema sought to eliminate the color blue as much as possible, feeling it was too well associated with the sci-fi genre.

Consequently, a supporting character played by Chris Cooper that was the subject of a documentary within the film was removed from the final cut.

[29] Several scenes included fictional video games; these sequences were developed by animation artist David OReilly.

His work on the film inspired him to explore developing his own video games, eventually leading to his first title, Mountain.

[36] In addition to the score, Arcade Fire also wrote the song "Supersymmetry" for the film, which also appears on their album Reflektor.

[41] Finally, on February 10, 2021, Arcade Fire announced that the score would be available for the first time digitally, on white-colored vinyl, and on cassette on March 19, 2021.

The site's critical consensus reads, "Sweet, soulful, and smart, Spike Jonze's Her uses its just-barely-sci-fi scenario to impart wryly funny wisdom about the state of modern human relationships.

[54] Rolling Stone's Peter Travers awarded the film three and a half stars out of four and particularly praised Johansson's performance, stating that she "speaks Samantha in tones sweet, sexy, caring, manipulative and scary" and that her "vocal tour de force is award-worthy".

Corliss cited HAL 9000 and S1m0ne as cinematic predecessors to Her and praised Johansson, calling her performance "seductive and winning".

[8] Todd McCarthy of The Hollywood Reporter called it "a probing, inquisitive work of a very high order", although he expressed disappointment that the ending is more conventional than the rest of the film.

He also praised Jonze's writing for its insights into what people want out of love and relationships, as well as the acting performances that "[make] it all feel spontaneous and urgent.

"[56] Richard Roeper said that the film was "one of the more original, hilarious and even heartbreaking stories of the year" and called Phoenix "perfectly cast".

[57] Manohla Dargis of The New York Times named it "at once a brilliant conceptual gag and a deeply sincere romance.

[60] Liam Lacey of The Globe and Mail said that the film was "gentle and weird", praised its humor, and opined that it was more similar to Charlie Kaufman's Synecdoche, New York than Jonze's Being John Malkovich and Adaptation.

Lacey also stated that Phoenix's performance was "authentically vulnerable" but that "his emotionally arrested development also begins to weigh the film down.

"[61] Conversely, Mick LaSalle of the San Francisco Chronicle criticized the story, pacing, and Phoenix's character.

[63] Stephanie Zacharek of The Village Voice opined that Jonze was "so entranced with his central conceit that he can barely move beyond it", and criticized the dialogue as being "premeditated".

At the same time, she praised Johannson's performance, calling it "the movie's saving grace", and stating that Her "isn't just unimaginable without Johansson—it might have been unbearable without her.

At the Academy Awards, the film was nominated in five categories, including Best Picture, with Jonze winning for Best Original Screenplay.

[76] A retrospective article from Wired similarly discussed its portrayal of AI-human relationships, with Kate Knibbs noting its more optimistic viewpoint of artificial general intelligence.