The film revolves around a video game live streamer's struggle for survival as he is forced to stay alone in his apartment in Seoul during a zombie apocalypse.

Though the emergency power stays on, Joon-woo gradually loses access to phone networks, the internet, and running water.

Yoo-bin tries to set up a zip line between their apartments by tying a cable to her table and throwing the other end to Joon-woo, but it lands in the street.

Joon-woo uses his drone to set up another line successfully, but an infected firefighter pulls on the first cable, causing Yoo-bin's table to fly across her apartment, knock her out, and lodge into her balcony railing.

A voiceover by an anchor explains wireless networks are being restored and the military is rescuing survivors who made social media posts.

#Alive is a zombie thriller[10] based on the original script "#Alone" of Hollywood screenwriter Matt Naylor, who worked on the American documentary series Small Business Revolution: Main Street and the short film What It’s Like.

[14] The full musical score was composed by Kim Tae-sung which he co-arranged with Choi Jung-in, Shin Hyun-pil, Park Sang-woo and Yoo Chae-young.

[21][8] Following its release, #Alive entered the all-time Netflix top 10 non-English language movies but has since dropped out with 54.62 million hours watched in the first 28 days.

#Alive topped the Netflix daily chart in 35 countries, including the United States, France, Spain, Sweden, Russia, Australia, Pakistan, and Canada.

The website's consensus reads: "Well-acted, genuinely unsettling, and occasionally even funny, #Alive proves the crowded zombie genre still has fresh stories to tell.

[38] Marian Phillips from Screen Rant wrote, "#Alive accurately captures the same panic, fear, uncertainty, loneliness, and isolation experienced by many during the pandemic's early days.

[...] By taking a concept unfamiliar to the sub-genre, #Alive transforms how zombie movies can be handled as well as providing an exploration of the different circumstances individuals find themselves when dealing with the apocalypse.

"[39] Anthony Kao from Cinema Escapist suggested, "#Alive is an entertaining zombie flick that seems tailor-made for the time of coronavirus.

[...] On top of its empathetic and socially relevant depiction of the Korean millennial condition, #Alive presents a narrative that feels unpretentious and accessibly entertaining.

"[40] The New York Times' Elisabeth Vincentelli concluded, "#Alive is a nifty little thriller that proves that you can always find signs of life in the most undead of genres.