World Transfer

World Transfer (LAN Host Handoff)

World Transfer lets you hand your LAN world to another player without anyone losing their inventory, position, or stats.

Normally, sending someone your world makes them spawn as you. World Transfer creates a ZIP (and sends it over LAN if possible) where the recipient becomes host but stays themselves. Everyone else who rejoins keeps their own data too.

Watch Demo: mp4, gif.

Usage

If a ZIP is enough and the host doesn't mind sending it over himself, the mod can only be on the host's (server) side. For the mod to send the world over LAN, it needs to be on the client that's currently hosting and on whoever's about to become the new host (server + client) too.

1. Host a LAN world with the mod (and Fabric API or NeoForge) installed.

2. Open the pause menu and click the WT button next to Save and Quit.

3. Pick a connected player from the list, then choose how to hand it over:

   • Send to <name> - sends the world straight over the existing LAN connection. Requires the recipient to have the mod installed too; if they don't, you'll be told and can fall back to a ZIP.
   • ZIP - builds an archive (from the world as it is in that instant, not a copy of whatever was last written to disk) and saves it to your Desktop (default) or your .minecraft folder. Send it to them yourself and have them unzip it into their saves folder.

4. Whichever route you used, they end up as the host, with their own inventory, health, XP, armor, and position. Everyone else who joins their LAN game keeps their own data too, the same way it always works in vanilla.

A direct send that's already been done once for a given world is incremental afterward - the receiving client checks what it already has (matched by a stable ID stored with the save, not the folder name) and only asks for what actually changed, rather than re-sending everything.

Your original world folder is never modified. The transfer only touches the copy that gets sent or zipped.

Receiving a transfer

• Direct send: an "Incoming world transfer" prompt pops up automatically with Accept/Decline. If you're mid-transfer already, or just want to check on it again, it's also listed inside the same WT menu, alongside the outgoing options.
• ZIP: unzip it into saves and open it from the singleplayer list like any other world.

Either way, opening the transferred world for the first time shows a message naming who handed it over to you and when - or a warning if the save doesn't actually name you as the intended recipient, which usually means the wrong ZIP got passed around.

Ownership history

Each world keeps a small log of who's hosted it and when, that travels with the save through every hand-off. It's viewable from the same WT menu.

Known limitations

• The ZIP captures the world at the moment you click Transfer. Anything that happens after that on your client won’t be in the file.
• Same-session UUID assumption. The name-based fallback (for when a player's UUID differs between sessions, e.g. switching online/offline) only helps if the player's name is unchanged. It won't help two different real people who happen to share a name.
• No resume for an interrupted direct send. If the connection drops mid-transfer, it has to be started over.
• No conflict handling for simultaneous transfers. The mod assumes one transfer completes before another is started from the same world.
• No block-level diffs. Incremental sync compares whole files (so a changed region file re-sends in full, not just the changed chunks inside it).
• Large first-time ZIPs. The ZIP route has no incremental option at all - every included folder is zipped in full.

Check full info & source code on the GitHub page.

Thanks for using my mod! You are welcome with any kind of suggestions or bug reports!