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Jellyfin

COLLAB
Velocity5.0

Free software media system for streaming and organizing personal media libraries

jellyfin.org ↗

Jellyfin renumbers to 12.0 and spends the whole cycle paying down its backend rewrite.

release-candidateperformancebackend-rewriteversioningself-hosted-mediadatabase
◆Current state
Jellyfin is deep in a 12.0 release-candidate train — five RCs since late June — that exists almost entirely to stabilize the backend rewrite shipped in 10.11.0. The project also renumbered along the way: 10.11.x becomes 12.x, dropping a leading "10." that had made every release read as minor. The outgoing 10.11.x stable line is still getting fixes, but 10.11.11 is down to a single locking change.
◆Where it's heading
The RC rounds are getting narrower as the train converges. RC1 was a cumulative dump covering the move to .NET 10, removal of legacy API route middleware and deprecated API members, and an HLS transcode seeking refactor; RC5 is batched database lookups and a fix for image endpoints upscaling past the source resolution. The 10.11.x branch is now being maintained mainly as an upgrade floor — 12.0 refuses to install on anything older than 10.10.7 and runs a multi-minute migration on first boot.
◆Prediction
With RC5 down to query batching and individual endpoint fixes, a 12.0 final looks near — likely one or two more RCs at most. The plugin story is the loose end: the RCs still tell testers to disable external plugins and reinstall from the unstable repository, and that has to resolve before a general release.

◆Recent moves

  1. 8d ago

    12.0 RC5: SQLite cache and batched lookups cut query load

    The fifth RC narrows to database and transcoding work: SQLite connections move to a private cache, people lookups and MediaSourceCount calls get batched, and image endpoints stop upscaling beyond the source resolution. This is the converging end of the 12.0 train — individually small changes aimed squarely at the rewrite's performance debt.

    View source ↗
  2. 16d ago

    12.0 RC4: MP4 track detection and SyncPlay queue fixes

    A routine RC round — dependency bumps, an MP4 audio and subtitle probe fix, and SyncPlay play-queue handling. Nothing here changes what the server can do; it is the maintenance layer between RC3's reporting rework and RC5's performance pass.

    View source ↗
  3. 28d ago

    12.0 RC3 reworks bitrate reporting, speeds book collections

    RC3 reworks bitrate reporting and fixes long-standing slowness in book collections, alongside session cleanup for dropped WebSockets that had been leaving SyncPlay groups stranded. These are precisely the rough edges the 12.0 cycle was opened to sand down.

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  4. 1mo ago

    12.0 RC2 revamps the startup UI, defers heavy DB tasks in scans

    RC2's visible change is a revamped startup UI, which carries more weight than usual because 12.0's first boot runs migrations that take minutes. The rest is database scheduling — heavy tasks no longer run during library scans, and large batch deletes no longer exceed the SQL variable limit.

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  5. 1mo ago

    Jellyfin drops the '10.' prefix and opens 12.0 on .NET 10

    ⚡ SPARK

    RC1 opens the 12.0 line and carries the entire delta from 10.11.x in one cumulative note: the move to .NET 10, removal of legacy API route middleware and deprecated API members, a rebuilt OpenAPI spec, an HLS transcode seeking refactor, and the renumbering that turns 10.11.x into 12.x. It is the only entry in this window that changes the shape of the product rather than polishing it.

    View source ↗
  6. 2mo ago

    10.11.11 adds a UserManager lock helper

    A single locking change in UserManager on the outgoing stable branch. 10.11.x is maintenance-only now, kept current mainly so servers have a supported floor to upgrade into 12.0 from.

    View source ↗