Need for Speed: Underground 2 in the browser
A fan project that runs the PC game Need for Speed: Underground 2 (2004) in Google Chrome and Firefox. The game's x86 code is translated to C ahead of time and compiled to WebAssembly. Direct3D 9 runs on WebGPU and the sound on Web Audio. You bring your own copy of the game.
Not affiliated with or endorsed by Electronic Arts. This repository contains none of the game's code or data.
What you need
- The game: your own PC copy, patched to v1.2 (North America), with this exact
SPEED2.EXE(other versions will not work): 4,800,512 bytes, SHA-256f9dd86c054878ce6276beb07c1fd61874f7a1e4bf1f241b084c65b73e24168a7. - To build: an Apple Silicon Mac (the tested setup) or Linux, Python 3, Node.js 20 or newer, and
wasi-sdk 34 for that system unpacked into
deps/. On Windows, build in WSL 2 with the clone in the Linux file system (~/nfsu2-web): under/mnt/cit builds much slower. - To play: the latest Google Chrome, or Firefox where it has WebGPU (Windows, macOS).
Build
python3 -m venv .venv && .venv/bin/pip install -r requirements.txt web/gen.sh "/path/to/Need for Speed Underground 2/SPEED2.EXE" # translate the game's code to C (into gen/) web/build.sh # compile it to out/web/nfsu2.wasm
The generated C and the compiled module are made from the game, so they are never committed (.gitignore).
Play
web/start.sh --data "/path/to/Need for Speed Underground 2"Open http://localhost:8080/ in Chrome or Firefox and press Play. The start page has the settings, your saves and the controls. The player's guide is docs/web/PLAYING.md.
To play with friends, run the server behind HTTPS, for example on a small VPS with Docker: docs/web/VPS.md. Everyone who plays from the same server can meet in free roam.
How it works
tools/: a Python lifter (Capstone) turns every function ofSPEED2.EXEinto C.runtime/: Windows, Direct3D 9, DirectSound and DirectInput, reimplemented.runtime/web/holds the browser parts.web/src/: the page. It runs the game's threads as workers on one shared memory, draws with WebGPU and plays sound through an AudioWorklet.web/server/: serves the page, the module and your game folder, and connects players for multiplayer.
More in docs/web/DESIGN.md. The same tree still builds the native macOS version
(./gen.sh, ./build.sh && ./link.sh, ./run.sh).
Credits
Based on Talha Müderrisoğlu's static recompilation of NFSU2 for Apple Silicon, which in turn follows the method of N64: Recompiled and XenonRecomp. Built with the help of Claude Code.
License
MIT (LICENSE). Need for Speed and Need for Speed: Underground 2 are trademarks of Electronic Arts Inc.