Desktop App custom dictionaries

<PlanAvailability slug="all-commercial" />

From Mattermost desktop app v4.7.1, custom dictionary definitions can be served through a URL on Windows and Linux. If custom dictionaries aren't specified, default dictionary definitions are obtained automatically from Chromium's CDNs (content delivery networks). On macOS, the Mattermost desktop app uses dictionary definitions provided by Apple that can't be customized.

Prepare custom dictionaries

On Windows and Linux, the Mattermost desktop app uses Hunspell Dictionary definitions by default. You can download a copy of these dictionary definitions and modify them to fit specific needs.

To access a copy of these dictionary definitions:

1. Download a copy of hunspell_dictionaries.zip from the latest electron release.
2. Extract the dictionary definitions from the ZIP file.
3. Convert the filenames to lowercase. (Chromium expects en-us rather than en-US). Once renamed, these definition files match the usage of using Chromium's CDN ones, and you can modify the definitions as needed.
4. Serve the extracted and converted files from a web server, and note the URL to the root folder of the dictionaries. Specify this URL as the alternate dictionary URL in the desktop app.

Configure the Desktop App

1. In the Mattermost Desktop App, go to Settings by selecting > File > Settings.
2. Under App Options, ensure that the Check spelling option is enabled.
3. Select Use an alternative dictionary URL to specify the URL to the root folder of your custom dictionaries, then select Save.

Remove custom dictionaries

Select Revert to default to stop using the specified dictionary definitions, and revert to default dictionary definitions.