The unofficial open-source project OpenSmash-Ultimate allows Super Smash Bros. Ultimate to run natively on Windows without requiring a traditional Switch emulator. Existing tests have successfully run full matches at 60 FPS.
The project opened to testers on October 19, 2026, and currently supports game versions 13.0.4 and 13.0.5. Its technical approach involves converting AArch64 machine code into C language code, which is then compiled into a Windows x64 program. It also reimplements the Switch system services required by the game and translates Nintendo's NVN graphics interface to Vulkan.
In addition to full matches, the current version offers controller button remapping, resolution scaling, V-Sync, local save files, and experimental online play. The online mode leverages the game's local wireless functionality via LAN or internet connections and currently still uses a delay-based solution.
The developers plan to continue adding rollback netcode, reducing input latency, and striving for a stable 60 FPS across all modes, while also simplifying mod creation. Currently, move scripts for most fighters have been converted into readable C++ code.
The project does not distribute game files, assets, keys, or firmware; users must own the game and build the Windows version from their own copy. Although the project emphasizes that it contains no copyrighted game data, it remains uncertain whether Nintendo will take action against it.