What is Pyodide?

Pyodide is a Python distribution for the browser and Node.js based on 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 (throw an error in one language, catch it in the other), async/await, and much more.

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


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.


See 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 Governance and Decision-making.


If you use Pyodide for a scientific publication, we would appreciate citations. Please find us on Zenodo and use the citation for the version you are using. You can replace the full author list from there with “The Pyodide development team” like in the example below:

  author       = {The Pyodide development team},
  title        = {pyodide/pyodide},
  month        = aug,
  year         = 2021,
  publisher    = {Zenodo},
  version      = {0.19.0},
  doi          = {10.5281/zenodo.5156931},
  url          = {https://doi.org/10.5281/zenodo.5156931}


We accept donations to the Pyodide project at opencollective.com/pyodide. All donations are processed by the Open Source Collective – a nonprofit organization that acts as our fiscal host.

Funds will be mostly spent to organize in-person code sprints and to cover infrastructure costs for distributing packages built with Pyodide.


Pyodide uses the Mozilla Public License Version 2.0.

Infrastructure support

We would like to thank,