The best open source alternative to Jellyfin is Kodi. If that doesn't suit you, we've compiled a ranked list of other open source Jellyfin alternatives to help you find a suitable replacement.
Jellyfin alternatives are mainly Media Servers but may also be Media & Streaming Tools. Browse these if you want a narrower list of alternatives or looking for a specific functionality of Jellyfin.
Plays videos, music, TV shows, photos, and games from a single interface, with live TV, PVR recording, and broad format support across devices.

Kodi is a full media center built to run on your TV, turning any compatible device into an entertainment hub. It handles virtually every media type you own: movies, TV shows, music, photos, and even games. The interface is designed for big screens and remote controls, not mice, making it a natural fit for living room setups.
At its core, Kodi is a local media organizer. Point it at your collection and it pulls in artwork, cast info, genres, and episode details automatically. Your movie shelf becomes a browsable library. TV shows stay organized by season and episode. Music gets proper album art and playlist support, including party shuffle modes.
Beyond stored media, Kodi supports live TV and PVR recording through popular backends like Jellyfin, MythTV, Tvheadend, NextPVR, and MediaPortal. You can watch and record live broadcasts without leaving the interface.
Key capabilities include:
Kodi sits in a different category from media server tools like Emby or Plex. Those are built around streaming to clients; Kodi is the client itself, running directly on the playback device. It can, however, connect to various backends and network sources.
It's entirely community-built and free, with no subscription tiers or feature paywalls. Everything it does is available out of the box.