Compiling for the Web

Requirements

To compile export templates for the Web, the following is required:

See also

For a general overview of SCons usage for Godot, see Introduction to the buildsystem.

Building export templates

Before starting, confirm that emcc is available in your PATH. This is usually configured by the Emscripten SDK, e.g. when invoking emsdk activate and source ./emsdk_env.sh/emsdk_env.bat.

Open a terminal and navigate to the root directory of the engine source code. Then instruct SCons to build the JavaScript platform. Specify target as either release for a release build or release_debug for a debug build:

scons platform=javascript tools=no target=release
scons platform=javascript tools=no target=release_debug

By default, the JavaScript singleton will be built into the engine. Official export templates also have the JavaScript singleton enabled. Since eval() calls can be a security concern, the javascript_eval option can be used to build without the singleton:

scons platform=javascript tools=no target=release javascript_eval=no
scons platform=javascript tools=no target=release_debug javascript_eval=no

The engine will now be compiled to WebAssembly by Emscripten. Once finished, the resulting file will be placed in the bin subdirectory. Its name is godot.javascript.opt.zip for release or godot.javascript.opt.debug.zip for debug.

Finally, rename the zip archive to webassembly_release.zip for the release template:

mv bin/godot.javascript.opt.zip bin/webassembly_release.zip

And webassembly_debug.zip for the debug template:

mv bin/godot.javascript.opt.debug.zip bin/webassembly_debug.zip

Threads and GDNative

The default export templates do not include threads and GDNative support for performance and compatibility reasons. See the export page for more info.

You can build the export templates using the option threads_enabled=yes or gdnative_enabled=yes to enable threads or GDNative support:

scons platform=javascript tools=no threads_enabled=yes target=release
scons platform=javascript tools=no threads_enabled=yes target=release_debug

scons platform=javascript tools=no gdnative_enabled=yes target=release
scons platform=javascript tools=no gdnative_enabled=yes target=release_debug

Once finished, the resulting file will be placed in the bin subdirectory. Its name will have either the .threads or .gdnative suffix.

Finally, rename the zip archives to webassembly_release_threads.zip and webassembly_release_gdnative.zip for the release template:

mv bin/godot.javascript.opt.threads.zip bin/webassembly_threads_release.zip
mv bin/godot.javascript.opt.gdnative.zip bin/webassembly_gdnative_release.zip

And webassembly_debug_threads.zip and webassembly_debug_gdnative.zip for the debug template:

mv bin/godot.javascript.opt.debug.threads.zip bin/webassembly_threads_debug.zip
mv bin/godot.javascript.opt.debug.gdnative.zip bin/webassembly_gdnative_debug.zip

Building the editor

It is also possible to build a version of the Godot editor that can run in the browser. The editor version requires threads support and is not recommended over the native build. You can build the editor with:

scons platform=javascript tools=yes threads_enabled=yes target=release_debug

Once finished, the resulting file will be placed in the bin subdirectory. Its name will be godot.javascript.opt.tools.threads.zip. You can upload the zip content to your web server and visit it with your browser to use the editor.

Refer to the export page for the web server requirements.