The vocal performances in the film were recorded almost entirely live on set, specifically to ensure that Ben Platt's vocals sounded as genuine and authentic as possible when he sang on screen.
The stage musical has its origins in an incident that took place during Benj Pasek's high school years at Friends' Central School.
Ben Platt and Colton Ryan are the only two members of the original Broadway cast (Ryan being an understudy in that production) to return for Stephen Chbosky's film.
The character of Alana Beck was expanded upon for this adaptation with a new song being written for her (by the actress playing her, Amandla Stenberg, in collaboration with Pasek and Paul), and Larry Murphy was re-conceived as Connor and Zoe's step-father instead of their biological father as in stage version.
The musical's ending was altered for this film to, according to Ben Platt, "make Evan more accountable for his actions than he was on stage."