Built-in offline plugin

[MkDocs][mkdocs] is one of the few frameworks that allow to build offline-capable documentation that can be directly viewed by the user – no server needed. With the offline plugin, you can distribute the [site directory][mkdocs.site_dir] as a downloadable .zip file while retaining most interactive functionality.

Objective

How it works

After building your project, switch to the [site directory][mkdocs.site_dir] and open index.html in your browser – you're now viewing your documentation from your local file system! Most browsers will denote this by showing file:// in the address bar. However, you'll realize that the site search is gone.

Material for MkDocs offers many interactive features, some of which will not work from the local file system due to the restrictions of modern browsers. More specifically and technically, all calls to the Fetch API will error with a message like:

Cross origin requests are only supported for protocol schemes: http, [...]

While browsers impose those restriction for security reasons, it reduces the interactivity of your project. The offline plugin makes sure that site search keeps working by moving the search index to a JavaScript file, and leveraging @squidfunk's iframe-worker shim.

Additionally, the plugin automatically disables the [use_directory_urls] [mkdocs.use_directory_urls] setting, ensuring that users can open your documentation directly from the local file system.

There are some limitations.

When to use it

As the name already indicates, the plugin should only be used when you're building your project for offline distribution. It's also good to know, that the offline plugin plays nicely with the following other plugins, helping to create even better offline-capable documentation:

- :material-shield-account: __[Built-in privacy plugin][privacy]__ --- The privacy plugin makes it easy to use external assets when building for offline usage, as it automatically downloads them for distribution with your documentation. --- __Your documentation can work without connectivity to the internet[^1]__ - :material-rabbit: __[Built-in optimize plugin][optimize]__ --- The optimize plugin automatically identifies and optimizes all media files that you reference in your project by using compression and conversion techniques. --- __Your documentation can be distributed as a smaller `.zip` download__

[^1]: You might wonder why the privacy plugin is necessary to build truly offline-capable documentation with the offline plugin. While it's certainly possible to also add support for downloading external assets to the offline plugin, this functionality is already fully implemented in the privacy plugin and is its very raison d'être.

Material for MkDocs follows a modular approach for its plugin system – many
of the plugins work perfectly together and enhance each others
functionalities, allowing to solve complex problems with a few lines
of configuration.

Configuration

As with all built-in plugins, getting started with the offline plugin is straightforward. Just add the following lines to mkdocs.yml, and start building offline-capable documentation:

plugins:
  - offline

The offline plugin is built into Material for MkDocs and doesn't need to be installed.

General

The following settings are available:

Use this setting to enable or disable the plugin when building your project. If you want to build online- as well as offline-capable documentation, it's a good idea to use an [environment variable][mkdocs.env]:

plugins:
  - offline:
      enabled: !ENV [OFFLINE, false]

Limitations

When enabling the offline plugin, make sure to disable the following settings, as they make use of the Fetch API which will error when invoked from the local file system: