Super Mario 64 online on PC: sm64coopdx setup guide (2026)
sm64coopdx is the go-to way to play Super Mario 64 online on PC. It's a multiplayer project for the SM64 PC port that syncs enemies, events and every level between players, so everyone shares the same world. The Coop Deluxe Team maintains it as the official continuation of sm64ex-coop. It adds widescreen, uncapped FPS, a pile of options and a strong Lua modding API. The official site says lobbies hold up to 16 players. Checked against the official repo on Oct 13, 2026 (~1.4k stars).
Legal: CRT Forge links to official project repos only. We never host or link ROMs, ISOs or game dumps. Bring your own dump from a cartridge or disc you own. This isn't legal advice.
Step 1: get your Super Mario 64 ROM ready
You need your own .z64 dump of Super Mario 64. The US version is the safe pick: the repo's reference hash for it is SHA-1 9bef1128717f958171a4afac3ed78ee2bb4e86ce (sm64.us.sha1). Check yours at romhacking.net/hash.
Step 2: download sm64coopdx
Download the zip for your OS from github.com/coop-deluxe/sm64coopdx/releases and extract it. Skip "pre-patched" downloads from anywhere else.
Step 3: drag your ROM onto the window
Launch the game and, as the official site puts it, "drag and drop a .z64 ROM of SM64 onto the window to get started." Once your ROM is accepted you land on the main menu.
Step 4: host or join
| Mode | How it works | Setup |
|---|---|---|
| CoopNet public lobby | Hosted relay; shows under Join → Public Lobbies | Host → CoopNet → leave the password empty |
| CoopNet private lobby | Same relay, invite-only | Set a password, or invite through Discord (appearing offline blocks invites) |
| Direct Connection | You host the server on your own network | Forward UDP 7777 (default) on your router, or use Hamachi |
Mods and the Lua API
sm64coopdx is moddable in Lua, similar to Roblox and Garry's Mod. Start with the Lua docs. v1.5.1 completed documentation for 100% of the functions and added helpers like djui_console_is_open() and center_free_camera(). Mod creators publish on the project's official mod/forums site, linked from sm64coopdx.com. This is also a great sandbox for AI-assisted modding: give a coding agent the Lua docs and ask it for a small gameplay mod (see AI mods & mashups).
Build it yourself (optional)
The official wiki has compile guides for Windows (MSYS2), Linux, macOS ARM and macOS Intel, plus build flags like COOPNET.
sm64coopdx vs other SM64 PC ports
- n64decomp/sm64: the decompilation everything is built on.
- sm64-port: the plain single-player PC port.
- sm64coopdx: online co-op, mods, Lua API, active releases. The one to pick if you want to play with friends.
The official FAQ mentions an Android port being developed separately by community members; it isn't part of the main releases.
Related: best N64 PC ports, Perfect Dark PC port, SpaghettiKart, decomp hub, decomp launchers.
FAQ
What is sm64coopdx?
An online multiplayer project for the Super Mario 64 PC port that syncs enemies, events and every level between players. The Coop Deluxe Team maintains it as the official continuation of sm64ex-coop, with widescreen, uncapped FPS and a Lua modding API. The official site says lobbies hold up to 16 players.
Where do I download sm64coopdx?
Only from the official GitHub Releases page (github.com/coop-deluxe/sm64coopdx/releases) or the official site, sm64coopdx.com, which links there. The latest release we checked on Oct 13, 2026 is v1.5.1, published May 31, 2026 (US Eastern), with Windows, Linux, macOS (ARM and Intel) and SteamOS builds.
Do I need a ROM for sm64coopdx?
Yes. The official site says to drag and drop a .z64 ROM of Super Mario 64 onto the game window to get started. The repo's reference hash for the US ROM is SHA-1 9bef1128717f958171a4afac3ed78ee2bb4e86ce. CRT Forge never links ROMs.
How do I host an sm64coopdx game?
Press Host on the main menu and choose CoopNet or Direct Connection. With CoopNet, leave the password empty for a public lobby (listed under Join → Public Lobbies) or set one for a private lobby. Direct Connection needs a forwarded UDP port (7777 by default) or a VPN like Hamachi.
Is there a Steam Deck version?
v1.5.1 ships a SteamOS build, but the release notes say it's the last dedicated one: from v1.6, download the Linux build.
Can I make mods for sm64coopdx?
Yes. It's moddable through a Lua API (like Roblox or Garry's Mod). The docs live in the repo under docs/lua, and v1.5.1 completed documentation for 100% of the functions.