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Pyodide is a Python distribution for the browser and Node.js based on WebAssembly.

What is Pyodide?

Pyodide is a port of CPython to WebAssembly/Emscripten.

Pyodide makes it possible to install and run Python packages in the browser with micropip. Any pure Python package with a wheel available on PyPi is supported. Many packages with C extensions have also been ported for use with Pyodide. These include many general-purpose packages such as regex, PyYAML, lxml and scientific Python packages including NumPy, pandas, SciPy, Matplotlib, and scikit-learn.

Pyodide comes with a robust Javascript ⟺ Python foreign function interface so that you can freely mix these two languages in your code with minimal friction. This includes full support for error handling, async/await, and much more.

When used inside a browser, Python has full access to the Web APIs.

Try Pyodide (no installation needed)

Try Pyodide in a REPL directly in your browser. For further information, see the documentation.

Getting Started

Pyodide offers three different ways to get started depending on your needs and technical resources. These include:

  • Use a hosted distribution of Pyodide: see the Getting Started documentation.
  • Download a version of Pyodide from the releases page and serve it with a web server.
  • Build Pyodide from source
    • Build natively with make: primarily for Linux users who want to experiment or contribute back to the project.
    • Use a Docker image: recommended for Windows and macOS users and for Linux users who prefer a Debian-based Docker image with the dependencies already installed.


Pyodide was created in 2018 by Michael Droettboom at Mozilla as part of the Iodide project. Iodide is an experimental web-based notebook environment for literate scientific computing and communication.

Iodide is no longer maintained. If you want to use Pyodide in an interactive client-side notebook, see Pyodide notebook environments.


Please view the contributing guide for tips on filing issues, making changes, and submitting pull requests. Pyodide is an independent and community-driven open-source project. The decision-making process is outlined in the Project governance.



Pyodide uses the Mozilla Public License Version 2.0.