Media Server to Media Server

Before syncing between media servers (such as Plex and Jellyfin) confirm both servers contain the same movies and shows. Missing or different media cannot be synced!

Consider this only when:

• You understand the risks.
• Both servers have near-identical libraries.
• You have tested backup and restore on both servers.

Bidirectional sync between media servers carries the highest risk.

Both sides can introduce conflicts, duplicates, unintended overwrites, and propagated deletions.

For most users, one-way remains the safer choice.

"Same library" is rarely the same library

Common causes:

• Different ID's
• Different editions or cuts.
• Partial seasons.
• Extras and specials.
• 4K vs 1080p duplicates.

ID mismatches

Providers use different identifiers:

• Plex GUIDs
• Jellyfin/Emby internal IDs
• TMDb/TVDB/IMDb remaps

Small mismatches can write to the wrong item.

Mistakes cascade

One bad match on Server A copies to Server B. A later rematch makes B look wrong. Then you "fix" B and A flips back. That loop is hard to unwind.

Related topics

• Best practices - safer defaults.
• Trackers vs. Media Servers - pick a source of truth.