The Backrooms originated from a thread posted on the /x/ board of 4chan on 12 May 2019, where an anonymous user asked for others to "post disquieting images that just feel 'off'." There, the first photo depicting the Backrooms was uploaded, presenting a slightly tilted image of a yellow-colored hallway. Another anonymous user commented on the photo with the first story about the Backrooms, claiming that one enters the Backrooms when they "noclip out of reality in the wrong areas," which is a video game-related term originating from Source Engine games for when a player passes through a physical boundary that would otherwise block their way.

After the 4chan post gained fame, several Internet users wrote horror stories relating to The Backrooms. In addition, many memes were created and shared across social media, further popularizing the creepypasta. Some have also stated they had seen that image somewhere before; in the opinion of Manning Patston from Happy Mag, these comments were "existential, hollow, and terrified." Patston also commented on the use of the term "noclip", interpreting it as "glitches in which the walls of reality are torn down", such as the existence of doppelgängers. Comparing the location to the level design of the Resident Evil franchise, Kaitlyn Kubrick of Somag News called the Backrooms "the terrifying creepypasta of cursed dreams."

The location of the original Backrooms photo is unknown; although a number of locations have been proposed, it is also possible that the image is a procedurally generated digital composition. The creepypasta has also been associated with the concept of kenopsia, first coined in The Dictionary of Obscure Sorrows: "the eerie, forlorn atmosphere of a place that's usually bustling with people but is now abandoned and quiet".