Free up app storage

Free up Mattermost storage

Mattermost caches messages, images, and workspace files on this phone while you are signed in. Official docs: anything you can see in a channel is eligible for local storage, including attachments and profile images. Server history stays on your workspace. Files you download leave the app sandbox and can sit in Files or Downloads forever.

See how much space Mattermost is using

iPhone

1. Open the iPhone Settings app.
2. Tap General > iPhone Storage.
3. Tap Mattermost.

Android

1. Open your phone Settings > Apps.
2. Tap Mattermost.
3. Tap Storage or Storage and cache.

Mattermost does not have a WhatsApp-style Free up Storage screen. Use the system total, then clear cache or log out to drop the image cache.

Remove downloaded workspace files

1. In a channel, open a file you saved to the phone.
2. Delete the copy in Files or Downloads.
3. Ask a workspace admin before you delete the original from the channel. That file lives on the server for everyone.

Mattermost's mobile FAQ: once you download an attachment, it is outside the app's control and can remain on the device indefinitely.

Log out to clear the image cache

1. Open Mattermost and tap your profile picture.
2. Tap Log Out.
3. Sign back in to the server.

Official docs: logout removes session data, the image cache, and cached files for that server. Channel history comes back from the workspace. Use this when cache is the problem, not when you need to delete a server file.

Clear Mattermost cache on Android

1. Open your phone Settings > Apps > Mattermost.
2. Tap Storage or Storage and cache.
3. Tap Clear cache.

Do not tap Clear storage / Clear data unless you mean to reset Mattermost and sign in to every server again. Messages stay on the workspace.

iPhone does not offer a separate Mattermost cache button. Log out, or offload the app in iPhone Storage, if the system total stays high after you delete downloads.

Reinstall the app if storage is still high

If you already cleaned media and Mattermost still looks huge, a fresh install can clear leftover cache and temp files that are hard to reach by hand.

1. You do not need a chat backup. Channels and files stay on your Mattermost server. Save the server URL. Sign in again after reinstall.
2. Delete the app from your phone.
3. Restart your phone.
4. Install Mattermost again from the App Store or Google Play.
5. Sign in and restore from backup if the app offers it.

This often frees a lot of space. You may need to download some media again after restore.

What to do next

After Mattermost is lighter, check your photo library for duplicates and similar shots. That is what Dedupo is for.

More app guides: Free up app storage.