Some caution is needed. Xbox can't play PS5 games in any normal sense, and the best result reported so far runs at a frame rate that makes a slideshow look quick. Still, the project has clearly made progress, and it's interesting for anyone who follows Xbox Developer Mode, emulation or graphics API translation.
What's new this time
The port comes from the developer known online as @maccosmo. His fork is public on GitHub as Cosmo/KytyPS5, where it's described as a port of KytyPS5, "a PlayStation 5 translation layer," for Xbox Series consoles. It's released under GPL-2.0, and the current branch is named for October 12, 2026. According to Windows Central, the Xbox build:
- Runs as a UWP app under Xbox Developer Mode on Xbox Series X
- Adds a Direct3D 12 renderer and translates shaders with Mesa's spirv_to_dxil
- Runs Astro Bot at around 10 FPS on Series X, according to the report
The accompanying demo video is titled "Astro's Playroom (Controller Demo) on Xbox Series X." Astro's Playroom is the free game that came preinstalled on the PS5. Astro Bot is the separate full game released later. Windows Central gives its 10 FPS figure for Astro Bot, but the footage shows Playroom. Until the developer publishes clear per-title results, keep the two apart.
Windows Central also says the emulator plays Demon's Souls and Astro Bot at over 60 FPS, and that Marvel's Wolverine boots but runs too slowly to play. Read together with the 10 FPS Xbox figure, those numbers appear to describe KytyPS5 on desktop PCs, not the Series X port. Don't expect those results on a console.
Section summary: A public Xbox fork of KytyPS5 now boots Sony's own games on Series X, but the reported performance is far from playable.
How it got here: from Quake II to Astro
This isn't the project's first appearance. In September, TechPowerUp reported that Devran Cosmo Uenal had posted a video on September 8 of what he called a research project that ports the open-source KytyPS5 emulator to Microsoft's console through Developer Mode. At that point the port was called PS5X, and only four titles appear to be operational: GEX Trilogy, Hellboy: Web of Wyrd, Marvel Cosmic Invasion and Quake II, according to Notebookcheck.
Those early demos were rough. TechPowerUp said the video shows Quake II running somewhere between 25 FPS and 45 FPS, and that the game also dips below 20 FPS in some scenes, especially when it first boots up. The site also saw a marked jump in input latency, though it had no measurements.
WindowsForum's own coverage at the time noted that no public download is available. That has now changed: the fork's source code is public on GitHub. The library has also moved from indie and retro titles to games built by Sony's own studios. Running them badly is still a big step up from not running them.
Section summary: Over about five weeks the port went from four smaller games and no public code to first-party Sony games booting from a public repository.
Why DirectX is the hard part
The core problem is graphics. Upstream KytyPS5 renders through Vulkan, and Uenal explained back in September that the Xbox environment doesn't support Vulkan, which KytyPS5 uses for rendering, so the graphics side has to be adapted to DirectX. As TweakTown put it, progress made on the PC version of the emulator does not carry over automatically to the Xbox port.
The new Direct3D 12 renderer and spirv_to_dxil are how he's dealing with that. A simplified version of the chain:
- The PS5 game's GPU work is handled by KytyPS5's translation layer.
- Shaders end up as SPIR-V, the intermediate format Vulkan uses.
- Mesa's spirv_to_dxil converts them to DXIL, the shader format Direct3D 12 uses.
- The Xbox fork's D3D12 renderer sends that work to the Series X GPU.
Every one of those steps costs time. Windows Central notes there's "a lot of code translation happening," which goes a long way to explaining the 10 FPS. You'd expect hardware this similar to emulate well, but TechPowerUp made the point that running the heavier PS5 games using this emulator will be a big challenge, since the Series X and PS5 have generally similar hardware. Without the extra performance a high-end PC brings, there's no spare capacity to absorb the translation overhead.
There's also a question about how the code was written. Uenal mentioned using AI tools during development, particularly for converting code between graphics technologies, though he did not specify how central those tools were to the port, TweakTown reported. Windows Central wondered whether AI pushed the progress along. Neither the developer nor the reports say how much code AI produced, so we won't guess.
Section summary: Xbox doesn't support Vulkan, so every frame goes through a D3D12 translation layer. That's a big reason performance is low.
How Developer Mode fits in
This isn't a jailbreak. Developer Mode is a Microsoft feature for testing software on retail consoles. Talkesport, citing Microsoft's documentation, lists three requirements to turn it on: the Xbox Dev Mode app from the Microsoft Store, a Microsoft Partner Center app developer account, and an activation code entered on the Partner Center website. The same report says you can switch back to Retail Mode at any time, but retail games and apps don't run while the console is in Developer Mode.
The Xbox emulation scene has used Developer Mode for years. Talkesport notes that retro gamers have used the same mode for years to run emulators such as RetroArch on Xbox. That's why a UWP build matters: it uses the same app model Developer Mode already supports, and Windows Central says the fork runs on Windows as well.
If you want to try it, the most useful practical tip is to check Microsoft's current Developer Mode documentation and account terms before you start. Don't rely on old forum posts.
Section summary: The port uses Microsoft's own developer route, not a console exploit, but that means a Partner Center account and no retail games while it's active.
The legal fine print
The upstream KytyPS5 project says it is not affiliated with Sony Interactive Entertainment or PlayStation, does not distribute games or copyrighted system software, and tells users to use only legally obtained game files. Windows Report says the project does not include PS5 firmware or decryption keys, and the developer describes PS5X as a research project rather than a finished emulator.
None of that settles how individual users get their game files, and nothing reviewed here shows that the project breaks console security or exists to enable piracy. Windows Central asked its readers whether regulators should step in. That's a question for its readers, not a finding.
The timing is notable. Sony is pressing harder against PS5 modding: TweakTown says the company has been doing its best to shut down modding projects, most recently pushing Andy Nguyen to abandon his Linux PS5 work. Meanwhile Windows Central notes that PS5 jailbreaking has already put Xbox Cloud Gaming on Sony's console, and that another developer has Windows partly running on a PS5, with Hades playable. Each platform is now being used to run the other's software.
Our take
From a veteran's point of view, the impressive part isn't Astro at 10 FPS. It's that one developer has connected a PS5 translation layer, a SPIR-V-to-DXIL shader pipeline and the UWP sandbox into something that boots at all. Projects like this are often how graphics translation tooling gets tested in practice.
Be realistic about what it means for players, though. KytyPS5 upstream warns that compatibility, stability and performance vary between builds, with crashes and graphical glitches likely. The Xbox fork adds its own limitations on top of that. If you were hoping to save the cost of a PS5 to play Astro Bot, keep the receipt for your Series X and your expectations low.
Would you put your Series X into Developer Mode to try this? Tell us in the comments.
Update: Xbox fork now points to downloadable builds (October 19, 2026)
The Xbox KytyPS5 fork now directs users to downloadable Developer Mode builds and installation instructions, according to tbreak’s October 19 report. This goes beyond the public source-code availability noted above: prospective testers reportedly have a packaged-build route rather than only a repository to compile themselves. The developer’s current README lists releases for Xbox Series X|S, although that listing does not establish Series S game compatibility or performance.
The developer’s documentation also spells out a limitation beyond low frame rates: graphics operations the Xbox implementation cannot handle, including tessellation, are skipped. A game reaching gameplay therefore does not mean its visuals are complete, and the README explicitly warns that games working on PC may fail on Xbox.
Additional documented features include loading game folders and archives from USB storage, a swap file, and texture settings that trade detail for lower memory use. These provide more options for testing within the console’s constraints, but do not establish improved performance. Anyone experimenting should follow the Xbox-specific installation section: the repository warns that the desktop instructions farther down the same page do not apply to the console build.
Update: Developer reportedly demonstrates KytyPS5 on Xbox One (October 20, 2026)
KytyPS5 developer Devran Uenal has reportedly extended his experiments to Xbox One, according to XenoSpectrum’s October 20 report. Photos attributed to his demonstration show Quake II rendering an in-game scene and MARVEL Cosmic Invasion reaching its title screen on the older console. This is a claimed expansion beyond the Series X experiments, not an announcement of public Xbox One support.
According to XenoSpectrum, the Quake II image displays 20 FPS, while the MARVEL Cosmic Invasion title screen displays 60 FPS. Neither still establishes sustained performance, and the latter does not demonstrate gameplay at that speed. The build and settings used for the demonstration have not been disclosed.
For prospective testers, the important restriction remains: XenoSpectrum reports that the October 19 public release still supports only Xbox Series X|S and explicitly excludes Xbox One. The outlet also notes that the initial public build required AVX2 CPU instructions, which Xbox One lacks; how the experimental setup addressed that obstacle remains unexplained. Xbox One owners therefore should not treat these photos as evidence that the downloadable package will work on their consoles.