Building Emscripten from Source

Building from source allows you to access the very latest features and bug fixes, and is essential for developers who are Contributing to Emscripten.

There are two approaches to building from source:

  • Manually setting up the sources and dependencies.
  • Using the SDK package manager to set up the environment and get the sources.

The manual approach gives you a better understanding of the toolchain and all the build steps. The SDK method is easier because it automates and tests much of the setup process. It also enables a workflow where you can easily switch between source builds and SDK environments.


You can’t use both approaches at the same time because the SDK overwrites manual changes made to the user’s compiler configuration file.

The instructions for building Emscripten using both methods are given below, followed by guidance on how to update the configuration file and validate your environment once it is complete: