In context: QR codes were originally designed to efficiently track the types and quantities of automobile parts. Today, thanks to smartphones and mobile apps, their use has expanded far beyond that. If you really know your trade, you could even try packing a functional program into a single QR code – and maybe run Doom on it, because why not?

A resourceful developer named Kuber Mehta has taken the “Can it run Doom?” meme to new heights with a wild new project that pushes the boundaries of extremely limited execution environments. While the Backdooms project doesn’t technically run the original Doom engine inside a QR code, Mehta says he was directly inspired by id Software’s legendary shooter – as well as the viral “Backrooms” creepypasta – to develop his concept.

Backdooms is a compressed, self-extracting program encoded entirely within a single QR code. When scanned, it launches an infinitely generated HTML environment resembling Doom-style corridors, which players can navigate and interact with. The game runs entirely in modern web browsers and doesn’t require an internet connection – the entire game is stored in the URL itself.

Mehta, a computer science and artificial intelligence student in New Delhi, spent a week exploring how to maximize QR code storage and compression. He ultimately chose a Doom-like interactive experience to demonstrate his progress, but the same technique could, in theory, be used to encode lightweight web apps within QR codes, unlocking new possibilities for ultra-portable software delivery.

The developer chronicled his journey on the MindDump blog, where he explained the absurd premise – running code within a 3KB QR code – alongside the origin of the idea and the detailed process behind creating Backdooms. Notably, Mehta had to rely on a technique called minification – or in this case, extremely aggressive minification – to squeeze a functional HTML program into such a tiny space. This compressed code generates graphics, Doom-like corridors, enemies to shoot at, and even music.

A breakthrough came when Mehta received a helpful hint from a chatbot, which suggested using DecompressionStream – a little-known Web API available in all modern browsers. Thanks to this component, the Backdooms code can be dynamically decompressed and executed directly in the browser. The game can be played on desktops, smartphones, and potentially other devices via a link or by scanning the QR code available on the project’s GitHub page.

Though only loosely related to Doom, Backdooms keeps the “Can it run Doom?” tradition alive. Developers continue to push the boundaries of where the open-source FPS engine can run. Recent feats include running Doom on a Collector’s Edition game box, inside TypeScript’s type system, within a Microsoft Word document, and even directly on a GPU.