# Opening a file from an external URL

```{warning}
The third-party extension mentioned in this guide is not included in JupyterLite by default.
There might be other JupyterLab extensions achieving the same behavior, that
you might want to consider.
This guide is provided as a reference and for convenience to show how you can enable such feature
in your JupyterLite site.
```

By default in JupyterLite it is not possible to open a file from an external URL.

However you can install the
[jupyterlab-open-url-parameter](https://github.com/jupyterlab-contrib/jupyterlab-open-url-parameter)
extension to enable this feature.

In your build environment, install the extension:

```shell
pip install jupyterlab-open-url-parameter
```

Then build your JupyterLite site as usual:

```shell
jupyter lite build
```

The extension should be automatically enabled in your site.

The extension will open a file passed via a URL parameter. The URL parameter is
`fromURL`. It is possible to pass multiple files via the `fromURL` parameter. The files
will be opened in the order they are passed.

For example if you would like to open a notebook and a csv file:

- https://raw.githubusercontent.com/jupyterlab/jupyterlab-demo/master/notebooks/Lorenz.ipynb
- https://raw.githubusercontent.com/jupyterlab/jupyterlab-demo/master/data/iris.csv

You can append the following to the URL of your JupyterLab instance:
`?fromURL=https://raw.githubusercontent.com/jupyterlab/jupyterlab-demo/master/notebooks/Lorenz.ipynb&fromURL=https://raw.githubusercontent.com/jupyterlab/jupyterlab-demo/master/data/iris.csv`

Which will result in the following URL:

```
http://your-jupyterlite.example.com/lab?fromURL=https://raw.githubusercontent.com/jupyterlab/jupyterlab-demo/master/data/iris.csv&fromURL=https://raw.githubusercontent.com/jupyterlab/jupyterlab-demo/master/notebooks/Lorenz.ipynb
```

![a screenshot showing how to use the jupyterlab-open-url-parameter extension](https://user-images.githubusercontent.com/591645/230444694-5297f8b7-4558-4a9c-bb05-918e1cdde3bc.gif)

```{note}
For more information about the extension, check out the
[jupyterlab-open-url-parameter](https://github.com/jupyterlab-contrib/jupyterlab-open-url-parameter) repository.
```

## References

Check out the [guide for adding extensions](../configure/simple_extensions.md) to learn
more about how to add extensions to your JupyterLite site.