JupyterLite: Jupyter ❤️ WebAssembly & Python

JupyterLite is a JupyterLab distribution that runs entirely in the web browser, backed by in-browser language kernels.

:zap: Try it online


:sparkles: Highlights

Browser-based Interactive Computing

  • Python kernel backed by Pyodide running in a Web Worker
    • Initial support for interactive visualization libraries such as altair, bqplot,
      ipywidgets, matplotlib, and plotly
  • JavaScript and P5.js kernels running in an IFrame
  • View hosted example Notebooks and other files, then edit, save, and download from the
    browser’s IndexedDB (or localStorage)
  • Support for saving settings for JupyterLab/Lite core and federated extensions
  • Basic session and kernel management to have multiple kernels running at the same time
  • Support forCode Consoles

Ease of Deployment

  • Served via well-cacheable, static HTTP(S), locally or on most static web hosts
  • Embeddable within larger applications
  • Requires no dedicated application server much less a container orchestrator
  • Fine-grained configurability of page settings, including reuse of federated

For more info:

:mega: Check out the announcement blog post:

:bird: Like and retweet the announcement tweet:



Hey folks! It seems :santa: Père Noël came last night, and left some surprises in our shoes! :hiking_boot:

jupyterlite 0.1.0a18

jupyterlite 0.1.0a18 is on PyPI. Some of the new features have extra dependencies, so the quickest way to install everything is:

pip install jupyterlite=0.1.0a18[all]

Who cares?

0.1.0a18 (and the last couple releases) have gotten up to where a Lite site can be configured to be entirely self-hosted, such that it doesn’t rely on any third-party services at run-time.

Some build-time configuration options, introduced recently, that will download (or otherwise acquire) the needed assets and update config files:

  • pyodide_url will download the 180mb pyodide bz2 release
  • mathjax_dir will load 9mb of assets
    • automatic if jupyter-server-mathjax is installed
  • wheel_urls will download individual wheel URLs or paths, or index a local directory

Meanwhile, at run-time:

With this setup, a lite site can be entirely self-contained, meaning it can be:

  • shipped on a a USB stick and used offline with a local web server (e.g. python -m http.server)
  • shared on the distributed web with ipfs or dat
  • packaged as part of a web application

What’s next? (you can help!)

The last few releases have gotten really far towards something that can be useful, but it is a pretty complicated process. A serious documentation overhaul is being planned and feedback there would be very appreciated!

For a content creator, part of having a more documentable process might be integrating more closely with other, more familiar tools, such as sphinx or jupyter(lab) itself, to get content creators get more productive more quickly.

For developers, now that it’s possible to install third-party kernels, we’re hoping to see some new kernels, and best practices around building, deploying, and documenting them, for different communities. Some upcoming work will enable even more flexibility, with arbitrary “HTTP” and “WebSocket” routes.

Finally, we’ve added some baseline browser tests… but can always to do more!

Stay tuned!


jupyterlite 0.1.0a19 is out. This is an upstream-focused release, with new versions of JupyterLab & RetroLab as well as an interesting new version of pyodide which is interesting in its own right.

Of course, at basically the exact same time, IPython 8.0.0 also came out, and we haven’t tested it out in the browser yet. :blush:

Stay tuned for more stuff in 2022!


Skipped a month of updates, but things have been busy!

Stay tuned, hopeful more to come soon!