Dolphin for Web

GameCube and Wii emulation in your browser, powered by WebAssembly.

Live: dolphinweb.bitaxislabs.com

Features

• Dolphin emulator compiled to WebAssembly via Emscripten
• Software renderer (WebGL2 canvas output)
• Zero-copy ROM loading (files never leave your browser)
• On-screen GameCube touch controls with virtual analog sticks
• Nintendo Switch 2 NSO GameCube controller support via Web Bluetooth
• iOS Safari support (HTTPS + SharedArrayBuffer)
• Responsive layout for desktop and mobile

Requirements

• A modern browser with WebAssembly, SharedArrayBuffer, and Web Workers
• Chrome 85+, Safari 17+, Firefox 105+
• HTTPS required (for SharedArrayBuffer / COOP+COEP headers)
• Your own GameCube/Wii ROM files (not included)

Running Locally

The web/ directory contains everything needed to run. You just need an HTTP server that sets the correct headers.

cd web
python3 server.py

Then open http://localhost:8080 in your browser. The included server.py sets the required Cross-Origin-Opener-Policy and Cross-Origin-Embedder-Policy headers.

For iOS Safari testing (requires HTTPS):

cd web
# Generate a self-signed cert first:
openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -days 365 -nodes -subj '/CN=localhost'
python3 server_https.py

Building from Source

Prerequisites

• Emscripten SDK (3.1.x+)
• CMake 3.20+
• Python 3

Build Steps

# Clone with submodules
git clone --recursive https://github.com/bitaxislabs/DolphinWeb.git
cd DolphinWeb

# Activate Emscripten
source ~/emsdk/emsdk_env.sh

# Configure
cd dolphin
emcmake cmake -B build-wasm -S . \
  -DCMAKE_BUILD_TYPE=Release \
  -DENABLE_HEADLESS=ON \
  -DENABLE_NOGUI=ON \
  -DENABLE_QT=OFF \
  -DENABLE_TESTS=OFF \
  -DUSE_DISCORD_PRESENCE=OFF \
  -DWITH_OPTIM=OFF

# Build
cmake --build build-wasm -j$(nproc)

# Copy output to web directory
cp build-wasm/Binaries/dolphin-emu-nogui.{js,wasm,data} ../web/

Emscripten Link Flags

The key Emscripten flags are configured in dolphin/Source/Core/DolphinNoGUI/CMakeLists.txt:

• -pthread / -sUSE_PTHREADS=1 for multithreading
• -sOFFSCREENCANVAS_SUPPORT=1 for GL context on worker threads
• -sALLOW_MEMORY_GROWTH=1 for dynamic memory
• -sEXPORTED_FUNCTIONS for the controller input bridge
• --preload-file for Dolphin system files

Architecture

• CPU: CachedInterpreter backend (no native JIT in WASM)
• Video: Software Renderer with EGL/WebGL2 canvas output
• Audio: Not yet implemented
• Input: Web Bluetooth (NSW2 controllers) + on-screen touch controls
• Frontend: DolphinNoGUI with custom Emscripten platform layer

Key Source Modifications

All Emscripten-specific changes are guarded with #ifdef __EMSCRIPTEN__:

• DolphinNoGUI/PlatformEmscripten.cpp - Main loop via emscripten_set_main_loop
• DolphinNoGUI/EmscriptenInput.cpp - Web controller state bridge
• DolphinNoGUI/EmscriptenStubs.cpp - Platform stubs
• Common/MemArenaEmscripten.cpp - malloc-backed memory arena
• Core/System.cpp - Force single-core mode
• VideoCommon/VideoBackendBase.cpp - Force Software Renderer

Deploying

For Cloudflare Pages or similar static hosting, set the build output directory to web/ and ensure these response headers are set on all routes:

Cross-Origin-Opener-Policy: same-origin
Cross-Origin-Embedder-Policy: require-corp

A _headers file for Cloudflare Pages is included in web/.

Legal

This project does not include any Nintendo ROMs, BIOS files, or copyrighted game data. You must provide your own legally obtained game files.

Dolphin is licensed under GPL-2.0-or-later. See the dolphin submodule for full license.

Credits

Built by Bit-Axis Labs