By the end of November 2018, ahead of the release of Spider-Man: Into the Spider-Verse (2018) the following month, Sony Pictures Animation had begun developing a sequel[54] due to the "incredible buzz" surrounding the project.[55] The sequel was to continue the story of Miles Morales / Spider-Man,[56][57] working from "seeds [that were] planted" throughout the first film.[54] Joaquim Dos Santos and David Callaham were set to direct and write, respectively, with Amy Pascal returning from the first film as producer.
The other producers of the first film—Phil Lord, Christopher Miller, Avi Arad, and Christina Steinberg—were all also expected to return in some capacities.[54] The next month, Pascal revealed that the film would focus on Miles and Gwen Stacy / Spider-Woman, exploring a romance between the characters that was cut from the first film, and that the sequel would be a "launching pad" for a previously announced female-focused spin-off film featuring Gwen.Sony officially confirmed the sequel in November 2019, with Lord and Miller returning as producers and a release date of April 8, 2022, announced.[58] In April 2020, Sony shifted the film's release to October 7, 2022,[59]
In February 2021, Miller said that he and Lord were working on the film's screenplay with Callaham, and that Peter Ramsey would be an executive producer on the sequel after co-directing the first film.[60] That April, Kemp Powers and Justin K. Thompson were announced as co-directors alongside Dos Santos, and that all three had worked on the project since it began. (Thompson was production designer on the first film.) Arad and Steinberg were confirmed to return as producers with Lord, Miller and Pascal, with Alonzo Ruvalcaba co-producing and Aditya Sood, Into the Spider-Verse directors Bob Persichetti and Rodney Rothman, and Rebecca Karch and Brian Michael Bendis joining Ramsey as executive producers.
In December, Lord and Miller revealed that the film was being split into two parts: Spider-Man: Across the Spider-Verse (Part One) and (Part Two), because they had written the story they wanted to tell for the sequel and realized it was too much for one film. Work on both parts was taking place simultaneously.[62] The sequels were renamed in April 2022, becoming Spider-Man: Across the Spider-Verse and Spider-Man: Beyond the Spider-Verse.
Their release dates were shifted then, with Across the Spider-Verse pushed back to June 2, 2023.[63][64][65] Lord and Miller said that they had told Sony the sequel would be the same size as Into the Spider-Verse, but it ended up having the largest crew of any animated film ever, with around 1,000 people working on it.
They added that the film had 240 characters and would take place across six universes.[63] Characters that were considered to appear in Across the Spider-Verse but were ultimately rejected include versions of Green Goblin, Doctor Octopus, Kraven the Hunter, Mysterio, Electro, Shocker, Rhino, Hobgoblin, Chameleon, Puma, Leap-Frog, Alistair Smythe, Grizzly, Boomerang, Screwball, Big Wheel, Beetle, and Diamondhead.
Daniel Pemberton confirmed in December 2020 that he would return to compose the sequel's score. In December 2022, Lord and Miller confirmed that Metro Boomin would create music for its soundtrack. Several artists were featured on it, including 21 Savage, Swae Lee, Lil Wayne, Future, Nas, ASAP Rocky, Lil Uzi Vert, Wizkid, Coi Leray, Offset, Becky G, Shenseea, A Boogie wit da Hoodie, JID, Don Toliver, James Blake, and 2 Chainz.
For the Japanese release, an original song, "Realize" performed by Lisa, was featured. The film was supported by another single, "Mona Lisa" by Dominic Fike, released on June 2, 2023—the day of the film's premiere. Although originally set to be released as a track on the deluxe edition of the soundtrack album, a few days after its release, the track was removed. On June 23, 2023, it was announced that the track was added into some versions of Fike's second studio album Sunburn, which was released on July 7, 2023.
Though external to the film's score and soundtrack, Daniel Kaluuya also incorporated musical elements into his vocal performance as Spider-Punk / Hobie Brown.[105] Kaluuya elaborated that he searched for the word "Spider-Punk" on Spotify, hoping to find fan-made playlists.
He stated that after finding some he "would just listen to them, be like vibing out," helping him with the process of gauging the character's energy.[105] Kaluuya further noted that "he wanted the character's voice to feel like a song," and that a take in which he portrayed the character as "rapping, but in a punk style" would be the one used in the film.