Developer Install


To install ipywidgets from git, you will need:

  • npm version 3.x or later
    • Check your version by running npm -v from a terminal.
    • Note: If you install using sudo, you need to make sure that npm is also available in the PATH used with sudo.
  • the latest Jupyter notebook development release
    • Everything in the ipywidgets repository is developed using Jupyter notebook’s master branch.
    • If you want to have a copy of ipywidgets that works against a stable version of the notebook, checkout the appropriate tag.
    • See the Compatibility table.


  1. Clone the repo:

     git clone
  2. Navigate into the cloned repo and install:

     cd ipywidgets
     bash --sys-prefix

Rebuild after making changes

After you’ve made changes to jupyter-js-widgets if you want to test those changes, run the following commands, empty your browser’s cache, and refresh the page:

    cd widgetsnbextension
    npm run update
    cd ..

Tips and troubleshooting

  • If you have any problems with the above install procedure, make sure that permissions on npm and pip related install directories are correct.

  • Sometimes, it helps to clear cached files too by running git clean -dfx from the root of the cloned repository.

  • When you make changes to the Javascript and you’re not seeing the changes, it could be your browser is caching aggressively. Try clearing the browser’s cache. Try also using “incognito” or “private” browsing tabs to avoid caching.

  • If troubleshooting an upgrade and its build, you may need to do the following process:

    • Deep clean of the cloned repository:

      git clean -dfx .
    • Remove anything with widgetsnbextension in the name of files within the conda directory

    • Try reinstalling ipywidgets

Releasing new versions

See for a details on how to release new versions of ipywidgets to PyPI and jupyter-js-widgets on npm.


See for a details on how to run Python and Javascript tests.

Building documentation

See for a details on how to build the docs.