Offline media cache, downloads, rolling cache, playback cache, automatic cache and more

Symfonium offers many different cache and download solutions to fit most of the needs.

All the settings related to these functions are described at: Settings - Offline, Cache and Download

Playback cache

This is an optional cache built to reduce issues with bad network conditions. It allows to cache the currently playing media to disk and pre-cache the next songs in queue (in a configurable number depending on network connection).
This cache also helps reducing a lot of the network usage if you often play the same media. But the data is stored in a specific way optimized for this need. It does not allow to actually start a song when fully offline. And it does not guarantee that the data is present.

Note: You can use a setting to copy the media from the playback cache to an offline cache via rolling cache (See settings)

Offline cache and download (manual)

On most media, the action menu (from the three dots) contains an entry to cache or download your media.

The bottom sheet will give you details about the current status of the media and the different options (depending on your settings).

  • If you have a global setting to transcode downloads, you can override a specific cached media by clicking “Original”. Otherwise the cached file will be transcoded as per your settings.
  • If you have enabled the rolling cache, then you can enable the option to cache the media in the rolling cache (a fixed size cache where the oldest cached media are deleted when the maximum cache size is reached).
  • “Export to Downloads folder” allows you to export media to the Android Downloads folder. These downloaded files won’t be used by Symfonium for offline playback. This is only a helper function if you need to use the media files in other applications.

If the media are already cached, you can click on the “Remove from cache” button to remove the files from cache.

If the media were cached via an automatic rule or cached in the rolling cache, pressing the “Move to permanent cache” button ensures that the media is not removed from cache due to rule change or the rolling cache being full.

Automatic offline cache.

Symfonium supports different automatic offline cache rules.

  • Automatic caching of favorites (see settings)
  • Automatic caching of Playlist, Artist and Genre. Each time new media are added to any of those types, they are cached based on your settings.

To configure rules, select the “Configure auto offline cache” action menu entry on supported items.

You can then enable or disable the auto cache on that item. If you have a global transcoding setting enabled for offline cache, you can override it for this specific rule.


  • Media that were cached by Symfonium version 9.0 or higher though an automatic rule are automatically removed from the cache when they are no longer covered by any rule.
  • Automatic caching only stores files in the permanent cache to avoid infinite loops (e.g. if your rules cache more media than the rolling cache size).

Automatic media provider offline cache

You can edit your media provider and enable “Automatic media offline cache”, either for the whole provider or for selected media libraries. The global transcoding value set for offline cache will be applied when caching though this option.

Permanent Cache, Rolling Cache and Automatic Rules Cache differences

  • Media in the permanent cache are never removed from the cache unless you explicitly decide to remove them. There is no size limits in that cache - your storage device could run full.
  • Media in the rolling cache are removed when the cache reaches its maximum size. The oldest cached media are removed first.
  • Media cached by automatic rules (on artists, genres, playlists or via favorite caching) are automatically removed from the cache when they are no more part of any automatic rule (only valid for media cached after the update to Symfonium 9.0).

Note: You can move media that were cached in the rolling cache or via an automatic rule to the permanent cache through the media action menu “Offline cache and download” bottomsheet.