There are already several ways to watch a Jellyfin library on an iPhone. Some of them are good. Most of them are ports: clients that run on many platforms and as such are not well optimised for any of them, and they try to do too much, so the Jellyfin experience is not optimal.
JellyMold is a player written only for Jellyfin servers, and only for Apple platforms, so you get the best of both worlds.
The thing your server should not be doing
Some Jellyfin clients try to play a file they cannot handle, and the server steps in. It decodes the video, re-encodes it into something the client understands, and streams that instead. It is called transcoding, and it is the reason people end up putting a graphics card in a machine that otherwise sits in a cupboard doing nothing but holding files.
Transcoding is a workaround for a client that cannot play the file. It costs electricity, it costs money, it takes time to start, and it degrades the picture. You are watching a re-encode of the thing you own, not the thing you own.
JellyMold plays the file you have stored directly. It carries its own playback engine, built on FFmpeg, and decodes on the phone. Your server’s job is just to hand over the bytes.
The practical effect: your library plays as it is, your server stays quiet, and an old NAS is enough.
Built for one type of server, on purpose
A client that speaks to Jellyfin, Plex, Emby and a folder of files has to describe them all in the same vocabulary. Whatever any one of them does well gets flattened into whatever all of them can do.
JellyMold only talks to Jellyfin, which means it can use the parts of Jellyfin that a generic client has to ignore:
- Media segments become a skip button for the intro, or a skip that happens on its own if you would rather. The end of the outro is what starts the next episode.
- Trickplay images become real thumbnails while you scrub, not a guess.
- Several servers merge into a single library. The same film on two of them appears once. A series split across two, with seasons one to four here and five onwards there, is one series.
- The subtitle providers your server is configured with are the subtitle providers the app offers.
Native is a claim that has to be earned
Plenty of apps say native and mean “wrapped a website”. The test is whether the things Apple’s platforms do well actually work.
We’re able to utilise all of the Apple goodies by being as native as possible. Picture in Picture is a real floating window. Episodes change without a gap, because the render stack stays alive across the switch rather than being torn down and rebuilt. Downloads are complete files kept where iOS will not quietly delete them when storage runs short, which it does to cached data, without asking, and which is catastrophic for the film you saved for a flight. On iPad there is a sidebar, keyboard shortcuts, and proper external display support.
Surround audio is downmixed for dialogue rather than loudness, because the most common complaint about watching anything at home is not being able to hear what anyone said.
What we cannot see
JellyMold has no analytics, no advertising, and no crash-reporting SDK. We cannot see your servers, your library, or what you watch, because none of it is ever sent to us.
That is not a marketing position, it is an architectural one. There is no account to make, and nothing to opt out of. Your media stays between you and a machine you own.
Where it is
JellyMold is in TestFlight now and launching soon on iPhone and iPad. tvOS is in development and will be part of the same app subscription when it launches. Family sharing is enabled, so it’s a single subscription per household. The app has a 3-month free trial if you choose the annual plan to make sure you’re sure it’s a good fit for you. Developing and maintaining an app like this takes time and effort, so the product is subscription only, and we’ve tried to make that low-cost and reasonable.
If you run a Jellyfin server and want to try it, ask for a place on our TestFlight. If you would rather wait for the release, leave your email anyway and we will tell you when it lands.