Stevens created the record mostly by himself in his home studio with contributions by several friends,[2] including harmonies provided by Adrienne Maree Brown, Hannah Cohen, Pauline Delassus, Megan Lui, and Nedelle Torrisi, among others.

[10] On Javelin's release day, Stevens posted on Instagram that "this album is dedicated to the light of my life, my beloved partner and best friend Evans Richardson, who passed away in April [2023]".

[21] Pitchfork awarded the album their "Best New Music" distinction, with Sam Sodomsky writing that "the songwriting feels as raw and direct as ever" as Stevens "seems intent on understanding and being understood, with the purpose of exposing the common thread between his pet subjects: raising the endless questions that lead us to seek meaning in one another, and rejoicing in the euphoria of sometimes finding it".

"[14] NME's Hannah Mylrea called it "a return to 'full singer-songwriter' Stevens, in a way, but by bringing together sonics from throughout his career and coupling it with frank and intimate lyricism, the gorgeous Javelin feels like a fresh take from the cult hero.

[15] Matthew Kim of The Line of Best Fit found that "Stevens goes back to what he does best – slightly electronic folk music paired with poetic lyricism – and he crafts yet another masterpiece, distinct from his previous catalogue but just as affecting".