On September 7, 2026, the open-source project Jellyfin shipped version 12.0, one of the biggest updates in its history. The self-hosted media server software gains native support for books and comics for the first time, along with substantial performance improvements for large libraries.
The new database pays off
The database structure introduced in version 10.11 now delivers noticeable speed gains. Playlists and collections store each item as a separate row, speeding up counting, pagination and editing of large libraries without having to load the entire collection. Series can now carry multiple versions with separate resume tracking – previously a movies-only feature – for example for broadcast and extended cuts.
Books, comics and a modern web interface
Jellyfin now extracts metadata from OPF and ComicInfo files as well as audiobook chapters server-side, without plugins. A redesigned reading interface supports PDFs, EPUBs and comics with unified fullscreen and swipe navigation. The formerly experimental “Modern” layout is now the default on desktop and mobile, using refreshed themes built on CSS variables. Under the hood, the project has moved to FFmpeg 8.1.
Security holes closed – but breaking changes remain
Several fixes address directory traversal, unsafe plugin handling and cross-site scripting. The cost: plugins must be retargeted to .NET 10, the legacy /emby/ and /mediabrowser/ endpoints are gone, and deprecated authentication mechanisms are disabled. Anyone upgrading should take a full backup of the data directory beforehand.
Source: Jellyfin – version 12.0 release announcement (jellyfin.org, September 7, 2026).
