Free up app storage

Free up Slack storage

Slack caches messages, images, and files from your workspaces so channels open fast. Files you download also sit on the phone. Messages stay in the workspace. Clearing cache does not delete Slack history on the server.

See how much space Slack is using

iPhone

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

Android

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

Reset Slack cache in the app

iPhone

1. Open Slack and tap your profile picture.
2. Tap Preferences.
3. Under Device & Troubleshooting, tap Debug & Reset Cache.
4. Tap Reset Cache.

Android

1. Open Slack and tap your profile picture.
2. Tap Preferences.
3. Tap Reset Cache.

Channels and DMs stay in the workspace. Slack may take a moment to reload recent messages.

Reset cache from iPhone Settings

1. Open iPhone Settings and scroll to Slack.
2. Turn on Reset Cache on Next Launch.
3. Open Slack.

Slack's help notes that this can sign you out of every workspace. Use the in-app reset first if you want to stay signed in.

Clear Slack cache on Android

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

Do not tap Clear storage / Clear data unless you mean to sign out of every workspace and reset the app.

Remove downloaded files

1. In a channel or DM, open a large file you downloaded.
2. If Slack saved a copy to Files or Downloads, delete that copy in the Files / Downloads app.
3. Ask a workspace owner to delete unused files in Slack if the workspace itself is the source of the bloat (that is workspace storage, not just this phone).

Clearing the app cache does not always remove files you saved outside Slack.

Reinstall the app if storage is still high

If you already cleaned media and Slack 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. Workspace messages stay on Slack. You will sign in to each workspace again after reinstall.
2. Delete the app from your phone.
3. Restart your phone.
4. Install Slack 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 Slack is lighter, check your photo library for duplicates and similar shots. That is what Dedupo is for.

More app guides: Free up app storage.