Pyodide 314.0 Release | Pyodide blog<br>Table of ContentsPEP 783 is Accepted: What Does It Mean?<br>New Versioning Scheme<br>Standard Library Changes<br>Pyodide Is Now a Native ES Module<br>Experimental Support for Socket Operations in Node.js<br>JavaScript Interop ImprovementsJsBigInt: Proper bigint roundtripping<br>JavaScript Resource Management and Python Context Managers<br>Better Array-like Support for JsProxy

Acknowledgements

We are pleased to announce the Pyodide 314.0 release.<br>This release focuses on standardization and packaging, marking a significant milestone in the Python-in-the-browser ecosystem.<br>PEP 783 is Accepted: What Does It Mean?#<br>The acceptance of PEP 783: Emscripten packaging marks perhaps the most exciting change in the history of the Python-in-the-browser ecosystem. Pyodide maintainers—especially @hoodmane—have poured an immense amount of effort into this over a very long time. Achieving this long-standing goal will expand our ecosystem exponentially.<br>What does this mean in practice? You can now publish Python packages built for Pyodide (or any Python runtime compatible with the PyEmscripten platform defined in PEP 783) directly to PyPI and install them at runtime.<br>Previously, the Pyodide maintainers had to maintain, build, and host over 300 packages ourselves. This created a significant burden on our maintainers and became a major bottleneck for the community, as every new package required manual review.<br>Moving forward, package maintainers can simply build and publish Pyodide wheels to PyPI, just as they do for native wheels on Linux, macOS, or Windows. By the time you are reading this, cibuildwheel v4.0 already supports building for the PyEmscripten 2025 and 2026 ABIs. The 2026 ABI is currently for our prerelease build only and thus needs to be enabled via the pyodide-prerelease option, but we will update cibuildwheel and make 314.0 stable available in a v4.1.0 release soon.<br>We&rsquo;ve written a comprehensive guide on building and publishing Pyodide wheels to PyPI. You can find it in the pyodide-build documentation.<br>If you are a maintainer of a Python package that uses PyO3 or maturin, there is also a good article written by Victorien Plot from the Pydantic team that explains how to build and publish PyEmscripten wheels.<br>With PEP 783 now formally accepted, the platform tags now use the pyemscripten_* prefix: pyemscripten_2025_0 for Python 3.13 (Pyodide 0.29.x) and pyemscripten_2026_0 for Python 3.14 (Pyodide 314.x). If you build wheels for either of these versions, update your build configurations and pyodide-build version accordingly.<br>New Versioning Scheme#<br>You might be wondering: wasn&rsquo;t the last version 0.29, and now it&rsquo;s 314.0?<br>Yes, we&rsquo;re updating Pyodide&rsquo;s versioning scheme in alignment with these new packaging standards.<br>To fully standardize the packaging process under PEP 783, we wanted to stabilize platform compatibility for packages so they don&rsquo;t break with every Pyodide release. Therefore, we&rsquo;re transitioning to a Python-version-based versioning scheme. For example, Pyodide 314.x directly corresponds to Python 3.14.<br>Whenever we make binary-incompatible changes, they will now align strictly with upstream Python updates (typically once a year). This means you can safely use existing packages built for the same Python version across multiple Pyodide releases. We plan to release a new major Pyodide version annually, synchronized with Python updates.<br>This first release in the new scheme ships Python 3.14.2 and Emscripten 5.0.3.<br>See also: Pyodide Issue #6084 for more context.<br>Standard Library Changes#<br>Originally, Pyodide &ldquo;unvendored&rdquo; several Python standard libraries, including ssl, sqlite3, and lzma.<br>This was done to reduce the Pyodide distribution size, enabling faster startup times while allowing users to install these packages after loading Pyodide when needed.<br>For example, if your application or package needed sqlite3, you would install it after loading Pyodide:<br>await pyodide.loadPackage("sqlite3");

However, with Pyodide now supporting PEP 783, we&rsquo;ve decided to restore these libraries to the standard library to provide a better user experience. This introduces a trade-off: while the initial download size increases, users no longer need to install these packages separately, creating a more seamless experience.<br>As part of this cleanup, the pydecimal and test packages have been removed from the distribution, and the fullstdlib option in loadPyodide() is now deprecated and has no effect.<br>We&rsquo;ve also decided to drop OpenSSL from the standard library, which would have introduced a substantial size increase when vendored. This results in two breaking changes:<br>The ssl module no longer relies on OpenSSL. We&rsquo;ve implemented a custom SSL implementation that provides basic features compatible with the standard library&rsquo;s ssl module, but without actual SSL/TLS support. Note that most of the ssl module&rsquo;s functionality didn&rsquo;t...