Super Smash Bros. Ultimate PC port (WindowSmash and OpenSmash-Ultimate)

Super Smash Bros. Ultimate came out on the Nintendo Switch in December 2018. Two fan projects appeared within a week of each other in October 2026: Denkishi created the ssbu-recomp repository on 12 October, and SNO2207 published WindowSmash on 18 October. DSOGaming reported WindowSmash’s first public release the same day. On 21 October both repositories moved to the OpenSmash-Ultimate organisation, WindowSmash switched to the GPL-3.0 licence, and a third repository, OpenSmash-Ultimate, began combining the two.

This site is not affiliated with SNO2207, Denkishi, Nintendo, Bandai Namco or Sora Ltd.

The projects side by side

All three repositories say they contain no game files, keys or firmware. Which to pick: the merged repository sends players to WindowSmash for now, so that is the main path. If your copy is 13.0.4, or you don’t have your firmware, ssbu-recomp is the one that accepts it, and its prebuilt runtime means fewer tools to install. We didn’t compare them ourselves.

How it works

• A static recompilation: the Switch uses an ARM processor, so its games cannot run on a PC as they are. Both projects find the functions in the game’s ARM64 code, write them out as C, and compile that into an ordinary PC program. Nothing is translated while you play.
• A runtime in place of the console: each project’s own code stands in for the parts of the Switch the game talks to: graphics (Direct3D 11 in WindowSmash, Vulkan in ssbu-recomp), sound, controllers, files and networking.
• Built on your PC: the repositories hold only the recompiler and the runtime. Your PC does the translation from your own copy, and the game keeps reading its data from your files.
• AI involvement: ssbu-recomp’s README says almost all of its code was written by AI coding agents (Claude) directed by the author. WindowSmash’s README says nothing about AI, but its commits carry a co-author line for Claude. We couldn’t confirm how much of WindowSmash was written that way.

More on the method: recompiled games list.

WindowSmash: current status

According to the README on 24 October 2026:

• up to eight controllers (Xbox, PlayStation, Switch Pro and most others) plus the keyboard;
• windowed, borderless or full screen, always 16:9, with settings for G-Sync and FreeSync monitors;
• online play through Local Wireless: rooms show up for everyone in the online lobby, with lobby codes for private groups and a host-and-join mode; the game’s own Online mode (Quickplay against WindowSmash’s own server) is new and being tested;
• your DLC fighters, Kazuya and Sora included, and a tool that unlocks the base-game roster on your own save;
• an experimental Linux version (install-windowsmash.sh) and an experimental macOS version for Apple silicon with macOS 14.5 or newer, drawn by its own Metal renderer and checked through the opening and menus but not in matches.

The project says 13.0.5’s menus and full roster have been checked, its matches less so. Complete matches between two PCs and the whole roster online are not yet verified, and testing with real controllers has been limited. On 24 October 2026 the open issues included reports of stutter, missing textures, models loading mid-match, missing DLC and GameCube adapter buttons swapped. The ready-to-run runtime package of the first alpha was withdrawn on 22 October; every player now builds from source. We didn’t play it ourselves.

ssbu-recomp: current status

From its README on 24 October 2026, measured on the author’s PC:

• works: boot, opening movie, title and menus, and a whole 1v1 match against the CPU to the results screen, at 59-60 fps on an NVIDIA GPU and on an Intel integrated GPU;
• starts and plays with scripted input: Classic Mode, Training and Home-Run Contest;
• reachable: Spirits, Vault, options, Mii Fighters; World of Light reaches its intro;
• not tested: team battles, Squad Strike, Tourney, three to eight players, Stage Builder editing;
• online: Local Wireless over a LAN, a room code or a lobby server is experimental; rollback netcode is in progress;
• controllers: up to eight through SDL3, tested with virtual devices but not yet confirmed on physical pads.

The installer finds keys and games in the folders of common Switch emulators, applies your update and DLC, and downloads a prebuilt runtime from the project’s GitHub releases (the project’s own code only, no game files). It credits WindowSmash for parts of its online code, used with permission.

What you need

• Your own copy of Super Smash Bros. Ultimate from your own Switch (a game card dump, an .nsp, or the game as installed in an emulator), and your console’s keys. For WindowSmash also your firmware and the game at 13.0.5 (the base game plus your own 13.0.5 update file works). For ssbu-recomp, 13.0.4 or 13.0.5 and no firmware.
• Compressed files (.nsz, .xcz) have to be converted back to .nsp or .xci first for WindowSmash.
• A 64-bit Windows 10 or 11 PC. WindowSmash asks for an AVX2 processor (4th-generation Intel Core or newer, or any AMD Ryzen), a DirectX 11 graphics card, 16 GB of RAM recommended, and about 60 GB of free space plus about 17 GB for your game files. ssbu-recomp asks for a GPU with a Vulkan 1.3 driver.

We don’t explain how to obtain or copy game data, keys or firmware.

How to install

At a high level, from the official READMEs:

• WindowSmash: on its GitHub page use Code → Download ZIP, extract it to a drive with about 60 GB free (outside OneDrive folders), run Install WindowSmash.bat, choose your game, keys and firmware folders and an online name, and wait for the build. When it says Done, start the Play SSBU shortcut. Running the installer again updates it.
• ssbu-recomp: download the repository’s ZIP from its GitHub page (not the files under Releases, which the installer fetches itself), run Install SSBU.bat, check what it found and press Install, then start Play SSBU.bat.

Windows may warn that the installer is unsigned. Many sites offer “Smash Ultimate PC download” installers, keys or ready-made builds: they are not affiliated with these projects and are often malware. The real projects are only on their official GitHub repositories, and neither ships the game.

Other Super Smash Bros. Ultimate projects

• ssbu-decomp by sbergeron42: a matching decompilation of the game’s code. It is research, not something you can play, and ssbu-recomp says its own work on it is paused.

Is it official, and is it legal?

• All of these are unofficial fan projects, not affiliated with or endorsed by Nintendo, and none connects to Nintendo’s online service.
• The repositories say they contain no game code, game assets, keys or firmware; on its merge, OpenSmash-Ultimate removed a few files from ssbu-recomp’s history that had been taken from the game. You build or run the program from a copy you own. Laws on copying your own games differ by country.
• Never share your game files, keys or the program generated from them; both projects ask users not to post them in issues.

Not working?

• The installer stops at the CPU check (WindowSmash): it needs a processor with AVX2.
• Your game version is refused: WindowSmash now builds 13.0.5 only; put your 13.0.5 update .nsp in the game folder and click Check files. ssbu-recomp accepts 13.0.4 or 13.0.5.
• Effects stutter the first time (WindowSmash): shaders compile when first used; leave preparing the shaders ticked, or run launchers\Prepare Shaders.bat.
• “ssbu_game_eh_o1.dll is missing” (ssbu-recomp): an antivirus usually removed the unsigned game file built on your PC; its README explains how to restore it and resume the install.
• A friend’s room doesn’t show up: everyone needs the same game version, and each project’s multiplayer guide covers the rest.

Other Nintendo projects on this site: the Mario Kart Wii PC port, Super Mario Galaxy on PC and the Wind Waker PC port.

Unofficial. This page is written by an independent directory. It is not made by, endorsed by or affiliated with Nintendo (developed by Bandai Namco Studios and Sora Ltd.) or OpenSmash-Ultimate team: SNO2207 (WindowSmash) and Denkishi (ssbu-recomp) (Super Smash Bros. Ultimate PC port (WindowSmash and OpenSmash-Ultimate)'s author). We do not host any files, and we never link to game files, ROMs or ISOs.