65,536 bytes. That is the budget. Sixty-four kilobytes: roughly the size of a small JPEG, a medium avatar image, a rounding error in a modern dependency tree. It is not enough for a single React component's source map.
It is enough for a film.
Clean Slate by Conspiracy (2021) is a real-time rendered short film that fits physically-based rendering, volumetric lighting, procedural textures, procedural geometry, and a fully synthesised soundtrack into a single Windows executable. It won the 64K Intro competition and the Crowd Favourite award at Revision 2021, the world's largest demoparty. It took The Meteoriks 2022 Best High-End Intro. It finished twenty bytes under the limit.
No pre-recorded video. No MP3s. No texture files. No imported models. No audio samples. No external assets of any kind. Everything generated from algorithms at runtime. Watch it.
The Team
Three people built this. BoyC wrote the engine and contributed additional graphics. Gargaj built the synthesiser, composed the music, and produced graphics. Zoom directed the visuals. A Hungarian demo group with decades of combined experience in the scene, working within constraints that most studios would dismiss as absurd before finishing the sentence.
The industry standard for a comparable visual experience involves teams of dozens, gigabytes of pre-rendered assets, and budgets measured in six figures. Conspiracy used three chairs and a hard limit.
What Fits in 64 KB
To appreciate what Clean Slate achieves, one must first appreciate what 64 KB actually is. The number is deceptive. We have lost all intuition for small sizes. Most developers cannot name the size of their own application's favicon, let alone reason about what fits in 65,536 bytes.
Clean Slate contains, within those 64 KB: a complete rendering engine with physically-based shading; volumetric lighting that scatters through fog and atmosphere; procedural geometry (every mesh generated mathematically, no imported models); procedural textures (no Photoshop, no image files); and a complete musical score synthesised in real time. The film runs for several minutes. It has camera work, scene transitions, mood, narrative. It is, by any reasonable definition, cinema.
Electron, by contrast, requires roughly 500 MB to display a text input field. The ratio is not close. It is not in the same postcode. Clean Slate delivers a cinematic experience in the space that a modern "lightweight" application uses for its loading spinner.
The Engine
The technical foundation is apEx, Conspiracy's in-house demo engine, under active development since 2014. apEx is both a runtime and a toolchain: it provides the rendering pipeline, the procedural generation framework, and the final executable packer. BoyC has refined it across multiple productions, each one tightening the feedback loop between authoring and output size.
The audio comes from V2, Gargaj's synthesiser. Every tone, every drum hit, every ambient pad is calculated in real time from oscillator definitions and effect chains stored as compact parameter blocks. No WAV files. No samples. No MIDI. Pure synthesis. The entire soundtrack exists as a few kilobytes of instrument definitions and a sequencer timeline.
The final step is compression. The executable is packed to squeeze every redundancy out of the binary. Twenty bytes of headroom remained. Not twenty kilobytes. Twenty bytes. That is the margin between shipping and disqualification. It is the equivalent of landing an aircraft with two metres of runway to spare, blindfolded, in a crosswind.
What Does Not Exist
It is worth listing what Clean Slate does not contain, because the list is instructive:
No external assets. No audio samples. No video frames. No texture files. No imported 3D models. No pre-baked lighting. No dependency manager. No package.json. No node_modules. No build pipeline beyond the compiler and the packer. No runtime framework. No abstraction layer between the code and the GPU.
Everything the viewer sees and hears is generated from first principles at the moment of execution. The executable is the source and the output simultaneously. There is no distinction between "build artefact" and "application" because there is nothing to build from. The mathematics is the content.
The Uncomfortable Comparison
While Conspiracy fits a cinematic experience into 64 KB, the industry ships 500 MB Electron applications for a notes tool. A to-do list requires a Chromium instance. A chat client outweighs its heaviest message by a factor of half a million. The median web page in 2025 transfers 558 KB of JavaScript, of which 44% never executes.
This is not a matter of different requirements. It is a matter of different standards. Conspiracy's standard is: every byte justifies its existence. The industry standard is: bytes are cheap, ship it. One of these standards produces Clean Slate. The other produces loading spinners.
The comparison is not entirely fair, of course. A production web application handles user input, network state, accessibility, internationalisation, error recovery. Clean Slate handles none of these. But the gap between 64 KB and 500 MB is not explained by accessibility features. It is explained by accumulated indifference.
Cultural Heritage
The demoscene has been doing this for forty years. Commodore 64, Amiga, Atari ST, DOS, Windows, Linux, fantasy consoles. Four decades of proving that constraint is not the enemy of creativity; it is the precondition. In 2020, UNESCO recognised the demoscene as intangible cultural heritage in Germany, Finland, and the Netherlands. Not as nostalgia. As a living art form.
Most developers have never heard of it. That is not a criticism of developers. It is a failure of an industry that spends billions on conferences about "developer experience" but has never once pointed at the demoscene and said: look at what is possible when you refuse to waste.
Clean Slate is not remarkable because it fits in 64 KB. It is remarkable because it proves that 64 KB is a choice, not a limitation. The rest of us simply choose not to try.