By its very nature, horror is designed to disturb, provoke, and scare its audience. As such, it comes as little surprise that horror has traditionally been the genre associated with the scariest movies of all time. However, cinema has played host to a number of offerings from outside the genre that are just as terrifying as the scariest horror film, if not more so. While film fans may primarily look to the best horror movies of all time for their cinematic scares, a film’s ability to terrify its audience is by no means limited to one genre.

https://screenrant.com/terrifying-non-horror-movies-based-on-a-true-story-list/