A media server does two jobs that are easy to conflate: it organizes a pile of video files into something browsable, and it streams them to whatever screen you are sitting in front of. The reason people start looking for a replacement is rarely the interface. It is that sign-in, remote access, and hardware transcoding increasingly route through a vendor's account and a paid tier, putting a middleman between you and files you already own. Open source media servers keep the whole loop on hardware you run: your library never checks in with anyone's cloud, the transcoding and multi-user features are not paywalled, and watching your own collection costs nothing beyond the machine it lives on.
Jellyfin is a Free Software Media System that puts you in control of managing and streaming your media. It runs as a dedicated server that organizes your movies, shows, music, and photos and serves them to end-user devices through apps for phones, tablets, TVs, and the web.
Kodi is a free and open source media player and entertainment hub for digital media. It runs as a native app on Android, Linux, macOS, iOS, and Windows, and is built to feel at home on a big-screen TV with a remote as the heart of a home theater PC.
Stremio is a modern media center that brings your video entertainment into one place. You discover, watch, and organize videos, movies, TV series, and TV channels through a single, clean interface.
Kavita is a self-hosted reading server for comics, manga, webtoons, EPUB, and PDF. You run it on your own machine and read in the browser, then share the collection with friends and family.
SMPlayer is a free media player for Windows, Linux, and macOS. It ships with built-in codecs that play virtually all audio and video formats, so there is nothing extra to install before pressing play. It is a front-end built on the mpv and MPlayer engines.
Match the tool to the shape of your setup, not just the interface.
For a direct Plex-style server: Jellyfin Jellyfin is the closest match to how Plex works: a dedicated server that organizes movies, shows, music, and photos and streams them to apps on phones, tablets, TVs, and the web, plus a built-in browser client. It descends from Emby and runs on Windows, macOS, and Linux, with no premium licenses or locked features, so hardware transcoding and multiple users are not gated behind a subscription.
For a living-room media center: Kodi Kodi runs directly on the device attached to the TV rather than as a server you reach from thin clients, which fits a single home theater PC. It plays most audio and video formats, scans your collection into a library with box art, descriptions, and fanart, and streams over the home network or the internet. Skins and add-ons let you reshape the interface, and it is governed by the non-profit XBMC Foundation.
For addon-driven viewing: Stremio Stremio organizes movies, TV series, and channels through installable addons instead of one fixed library, so you assemble the catalog and metadata you want. Its Board, Discover, and Meta Details flow moves from browsing to a title's page to playback, and the web client is open source and self-hostable with Docker if you would rather run it on your own infrastructure than the hosted service.
Plex bundles several jobs that open source servers tend to split apart, so the first thing to sort out is which of them you lean on. A household that streams mostly inside the house cares about library scanning, client apps, and subtitles. One that shares with people elsewhere cares about remote access, per-user isolation, and bandwidth, and has to decide whether it will run a domain, a reverse proxy, or a VPN. Jellyfin is the closest drop-in: descended from Emby and built as an alternative to both Emby and Plex, it scans the same folders and ships apps for phones, tablets, TVs, and the web with nothing behind a paid tier.
Two of the others answer different questions. Kodi is not a server reached from thin clients but a media center that runs on the TV box itself, playing local and network files behind a big-screen library of art and metadata, which suits a single living room more than a shared account. Stremio organizes viewing around installable addons rather than one fixed library, and its web client self-hosts with Docker. Both trade Plex's centralized sign-in and effortless discovery for playback that answers only to you.
Treat the move as a parallel rebuild, not a conversion. Keep Plex running, point the new server at the same media folders with read-only access, and test real playback on the exact devices your household uses before you switch anything. The files carry over untouched; Plex-specific posters, collections, sharing rules, and watch state may not, so export what you can first and plan cleanup around naming, season numbering, and external subtitles.
On a browser or a good TV app, often yes; the gap tends to show on specific smart TVs, phones, and game consoles. Jellyfin has native apps across most platforms and a built-in web client, but coverage still varies by device. The practical test is to install the clients your household actually uses and play a few real files before committing, rather than trusting a demo on one screen.
Usually not. Jellyfin, Kodi, and Stremio all scan existing folders and play common container and codec combinations directly. The real question is whether each client can direct play a given file; if it cannot, the server has to transcode, which adds CPU or GPU load. Before migrating, test a few large files, external subtitles, surround audio tracks, and high-bitrate videos on every kind of client you own.
Watch history is the least portable part of leaving Plex. You may be able to pull watched flags, ratings, and dates out through Plex's database or API, but whether the new server imports them cleanly is a separate matter, and per-user progress is harder than a simple watched marker. If history matters, export it first, keep the old database, and verify a small test import before you trust a full move.
It becomes your responsibility. Plex hides remote streaming behind server claiming and app discovery; a self-hosted server needs a stable network path, HTTPS, real authentication, and careful firewall rules, which most people handle with a reverse proxy or a VPN. The upside is that no third party sits in the connection. The cost is that you have to understand exactly who can reach the server and how their credentials are protected.
It can, but setup is more explicit. You need compatible hardware, supported codecs, the right drivers, and correct permissions when the server runs in a container or a restricted service account. Confirm the server is actually using the GPU under load rather than silently falling back to software, and test several simultaneous streams, since one file playing smoothly does not prove the box can handle a full household at once.
Sometimes, but do not assume the Plex workflow carries over. Some servers support downloading media to a phone or tablet through their apps, while others rely on browser caching or manual file transfer. Offline viewing also raises questions about subtitle selection, download quality, and storage cleanup. If watching on a plane or commute matters, test that specific flow on the real client before moving your main users across.
Treat live TV as its own project. It needs tuner support, guide data, recording rules, storage planning, and reliable transcoding for remote playback, and Plex users often underestimate how much scheduling behavior they depend on, like series recording, padding, and conflict handling. Keep the existing DVR running until the replacement has recorded and played back several real programs correctly, then retire the old setup.
