Nacho Vigalondo was inspired to create Open Windows after he was asked to create a thriller that heavily featured the Internet. He found writing the script a challenge, as he had to create the film's plot as well as give specific reasons for each window that opened and why the point of view would shift between the characters.
At one of the festivals the movie was screened at, the director said it was OK for the audience to slap him on their way out if they didn't like the movie.
The movie was filmed in real time, in order to make the plot more realistic to the viewer.
The film appealed to Sasha Grey, as she was a fan of Nacho Vigalondo's work but was also intrigued by the character of Jill as a public figure and as someone who has to deal with "criticism and scrutiny and online haters and cyber stalkers."
An earlier version of the film was done with actors Jerónimo Salas as Nick Chambers, Julia Peti as Jill Goddard and the rest of the cast played by the visual effects crew. This version was done to help Nacho Vigalondo and the crew to create the final final.