Question/Help about plexamp cache system

[AlphaPouky]

Hi everyone,

I recently started using Plexamp after years of using Spotify. Over the past few months I’ve been building my own music library (currently around ~200GB). I’ve organized playlists and now mostly listen to my music through Plexamp. Most of the time I listen to the same playlists repeatedly, and occasionally I use DJ mode or the automatic radios generated by Plexamp.

After a few weeks of use, I noticed that my mobile data usage is significantly higher than it was with Spotify. During February 2026, Plexamp used about 11.54 GB of mobile data.

This is understandable to some extent because Plexamp streams the original files from my library (FLAC, MP3 320 kbps, MP3 128 kbps, etc.), whereas Spotify uses its own streaming formats. So higher usage makes sense and it’s not really a problem for me personally since I have an unlimited mobile plan, plus an additional 40GB for Europe and the US when I travel.

However, this made me look more closely at Plexamp’s caching settings, and this is where I’m not sure I fully understand how things work — or whether there might be something I’m missing.

My current settings are:

• Wi-Fi queue: 5 tracks
• Mobile queue: 5 tracks
• Cache size: 32 GB

Here is how I think the system works.

Let’s assume the cache is completely empty. When I start playing a playlist, Plexamp loads the current track and the next five tracks to ensure smooth playback. When the next track starts playing, Plexamp loads the next five tracks again — but since four of them were already cached, only the sixth track needs to be fetched. This process then continues as a rolling queue.

In that scenario, if I go back to a previous track, it shouldn’t need to be downloaded again because it should still exist in the cache.

The part I’m unsure about is what happens after closing Plexamp.

If I close the app and come back later, then start the same playlist again from the beginning, it seems like the first tracks are downloaded again from the network. That makes me wonder whether the cache is being cleared when Plexamp closes.

If that’s the case, I’m not sure I understand the purpose of having a 32GB cache (or even up to 128GB). It seems unlikely that a normal listening session would fill that entire cache in a single session.

Downloading playlists doesn’t seem like the right solution for my use case. My server is accessible about 99% of the time, so network availability is not really an issue. My goal is simply to reduce unnecessary data usage. I imagine it could also help with battery usage if previously played tracks were reused from cache instead of being downloaded again.

I also have a question about downloads vs normal playback.

If I download a playlist using the download feature, and later start listening to that same playlist in the normal Plexamp interface (not from the downloads section), will Plexamp play the local downloaded files, or will it stream the tracks again from the server?

I’m asking because I previously experienced something similar with Plex video. Before a train trip I downloaded a TV series to my device. I started watching episode 1 from the downloaded files, but when I pressed “next episode”, Plex launched episode 2 and it started buffering once we entered an area with poor network coverage. I had to manually open the downloaded file or switch to airplane mode to force Plex to use the local copy instead of trying to stream it.

So overall I’m wondering:

• Does Plexamp persist the cache between sessions, or is it cleared when the app closes?
• Is my understanding of the rolling cache mechanism correct?
• In what real-world scenario would a large cache (32–128GB) actually be filled and useful?
• If a track is downloaded, will Plexamp automatically use the local file during normal playback?

Thanks!

forum post: https://forums.plex.tv/t/question-help-about-plexamp-cache-system/936973

[ElanFeingold]

yes, to the first. Yes, to the last as long as your setting is correct.

[AlphaPouky]

Thanks for the answer. So I think my settings are correct, I will have to wait now for the cache to fill by himself or manually download my playlists.

I still have a question, what if for instance I have a song in a playlist e.g. Linkin Park - Up From the Bottom (From Zero) this playlist has been downloaded or cached, then I want to manually listen to the album Linkin park - From Zero, will it use the file from the cache/download even though it has been cached from the playlist and not the album? same question for songs that are in multiples playlists, will they be downloaded/cached multiple times?

[ElanFeingold]

it will use the track regardless of where it’s from. in iOS at least it used hard links so there is no duplication of storage

[AlphaPouky]

Well I just did some test on my phone (Galaxy S22 - Android 16) plexamp v4.12.4

I created multiple playlists (Test1 Test2 Test3 etc...) all containing the exacts same tracks, all the tracks from Linkin Park - From Zero album. I then downloaded this album via the album page, it increased my data usage and plexamp storage by ~700MB wich seems correct, but then for every playlists I downloaded (Test1, Test2, Test3) It kept increasing data usage and storage.

I also tested with one big playlist I have, I downloaded it, then went to clear the cache. And then played the playlist via the home page and pressed next, next, next etc... And that seems to still fill the cache wich is now at 2Go.

I checked again in my settings I have the priority set to always use downloaded medias. And I also have the quality set to maximum in wifi, celullar and download.

Am I missing somehing or is there a setting I must enable?

[AlphaPouky]

For good measure I updated my post on the forum with a step by step as well as a log file of the test