Pyodide: a Python distribution based on WebAssembly

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

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, C++, and Rust extensions have also been ported for use with Pyodide. These include many general-purpose packages such as regex, PyYAML, and cryptography, 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 in a REPL directly in your browser. For further information, see the documentation.

• If you wish to use a hosted distribution of Pyodide: see the Getting Started documentation.
• If you wish to host Pyodide yourself, you can download Pyodide from the releases page and serve it with a web server.
• If you wish to use Pyodide with a bundler, see the documentation on Working with Bundlers
• If you are a Python package maintainer, see the documentation on building and testing Python packages.
• If you want to add a package to the Pyodide distribution, see the documentation on adding a package to the Pyodide distribution
• If you wish to experiment or contribute back to the Pyodide runtime, see the documentation on building Pyodide from source

The Pyodide project consists of the following components:

• A build of CPython with a few patches (https://github.com/pyodide/pyodide/tree/main/cpython/)
• A JS/Python foreign function interface (https://github.com/pyodide/pyodide/tree/main/src/core and https://github.com/pyodide/pyodide/tree/main/src/py)
• JavaScript code for creating and managing Pyodide interpreters (https://github.com/pyodide/pyodide/tree/main/src/js)
• A choice of Emscripten platform, which consists of a version + ABI-sensitive flags + static libraries to link. This is described here and implemented in (https://github.com/pyodide/pyodide/tree/main/Makefile.envs)
• A toolchain for cross compiling testing and installing packages for Pyodide.

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.

• Blog: blog.pyodide.org
• Mailing list: mail.python.org/mailman3/lists/pyodide.python.org/
• Twitter: twitter.com/pyodide
• Stack Overflow: stackoverflow.com/questions/tagged/pyodide
• Discord: Pyodide Discord

For a full list of current and historical sponsors, please see the Funding section of our About page.

Pyodide also has a large number of small donors. If you’re interested in supporting Pyodide, check out our OpenCollective and GitHub Sponsors pages.

• BrowserStack: This project is tested with BrowserStack

Pyodide uses the Mozilla Public License Version 2.0.