Free up Plex storage

The Plex app stores offline / synced movies and shows on this phone, plus artwork and a transcode playback cache. Your server library stays on the Plex server or Plex account. Removing an offline item only deletes the copy on this device.

See how much space Plex is using

iPhone

Open the iPhone Settings app.
Tap General > iPhone Storage.
Tap Plex.

Android

Open your phone Settings > Apps.
Tap Plex.
Tap Storage or Storage and cache.

Plex does not have a WhatsApp-style storage screen. Open Offline or Downloads / Sync in the app to see files on this phone.

Remove offline and synced media

Open Plex and go to Offline, Downloads, or the Sync / offline section (the label depends on your app version).
Open a movie or show.
Remove the offline copy or turn off sync for that item.

The title stays on your Plex server. Only the file downloaded to this phone is removed.

Change offline sync settings

Open Plex Settings (profile or menu).
Open Offline, Sync, or download quality.
Set a lower quality, limit how much can sync, and prefer Wi-Fi.

Transcode cache is usually on the server. The phone still keeps artwork, subtitles, and a playback buffer after you stream. Offline files are the large number.

Clear Plex cache on Android

Open your phone Settings > Apps > Plex.
Tap Storage or Storage and cache.
Tap Clear cache.

Do not tap Clear storage / Clear data unless you mean to reset Plex on this phone. That signs you out and removes local offline files. The server library stays where it is.

iPhone does not offer a separate Plex cache button. Remove offline items in the app, or offload Plex in iPhone Storage if the system total stays high.

Reinstall the app if storage is still high

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

Offline and synced titles will need to be re-downloaded after you sign in. Your Plex server and account keep the library, watch state, and playlists.
Delete the app from your phone.
Restart your phone.
Install Plex again from the App Store or Google Play.
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 Plex is lighter, check your photo library for duplicates and similar shots. That is what Dedupo is for.

More app guides: Free up app storage.