Move a Project Zomboid co-op save to a dedicated server

A co-op world started with the in game Host button can move to a dedicated server, as long as both run the same build. Copy the world folder from Zomboid/Saves/Multiplayer, the settings files from Zomboid/Server and the accounts file from Zomboid/db, then put them in the same places on the server under the same name. Single player saves are a different story: they are stored in a way multiplayer does not read, so there is no supported way to move one. For those, the honest answer is a fresh world on the server.

Which saves can move?

If your world is from Build 41, it can still move, but only to a server running Build 41. On Steam that build is the legacy41 branch.

Where are the files on my PC?

Everything is in the Zomboid folder in your user profile. On Windows that is C:\Users\<your name>\Zomboid. On Linux and macOS it is ~/Zomboid.

The name to look for is the one your co-op game used. If you never changed it when you pressed Host, it is servertest. For a world with that name, these are the pieces:

• Saves/Multiplayer/servertest/, the world itself: map, bases, items, vehicles and other players' characters.
• Server/servertest.ini, server settings such as mods, password and player limit.
• Server/servertest_SandboxVars.lua, the sandbox rules such as zombie count, loot and the utilities shutoff.
• Server/servertest_spawnregions.lua, if it exists.
• db/servertest.db, accounts and the whitelist.

Close the game fully before copying, so the last save is written. Then copy the whole Zomboid folder somewhere safe as a backup, before you touch anything.

How do I move it across?

1. Stop the dedicated server. A running server can overwrite files as you upload them.
2. Back up the server. If it already made a world of its own on first start, that world is about to be replaced.
3. Zip the world folder. Long running worlds hold thousands of small files, and a single zip uploads far more reliably.
4. Upload each piece to its matching folder. The world goes into Saves/Multiplayer, the .ini and .lua files into Server, the .db file into db.
5. Make the names agree. The server looks for files by its own save name. Either set the server to use your old name, or rename every file and the world folder to the server's name. All of them must match, including the _SandboxVars suffix.
6. Check the mods. Every mod the world used must be on the server with the same Workshop IDs and Mod IDs. A missing mod can stop a world from loading.
7. Check the ports. If your home setup changed DefaultPort or UDPPort in the .ini, set them to what the server needs.
8. Start the server and watch the console until it says it has started. Then join and walk to your base.

For a large world, an SFTP app such as FileZilla or WinSCP is the safer way to upload than a browser.

Will everyone keep their characters?

Players who joined your co-op game are stored with the world, so they usually come across when the whole save folder moves. They should log in with the same username and password they used before.

The host is the exception. In a co-op game, the host's character is kept separately from everyone else's, and a dedicated server does not pick it up the same way. Expect the host to start with a new character in a world that is otherwise intact. People have shared ways to rename the host's files and recover the character, but they vary by build, so do not count on them. The base, the loot and the cars are the part that matters, and a new character can walk home.

What if it goes wrong?

• A new, empty world appears. A name does not match, or the world folder landed in the wrong place. Check Saves/Multiplayer/<name>.
• Everyone starts over as a new character. The players data did not come with the world folder, or the names differ.
• The server crashes while loading. A mod is missing or on another version, or the world was made on a different build.
• Your settings changes vanish. You edited the .ini while the server was running. Stop, edit, then start.

On a server from this site

Our servers keep the Zomboid folder as .cache. With the server stopped, upload the world into .cache/Saves/Multiplayer, the settings files into .cache/Server and the accounts file into .cache/db. Then set Save name in Settings to the world's name and start it. The panel writes the ports, password and mod lines into the .ini on every start, so copy your old WorkshopItems= and Mods= values into the Workshop IDs and Mod IDs settings. Settings also has an FTP and SFTP login for big uploads, and there is a Backup button to press before you replace anything. If the world is from Build 41, pick the Build 41 (legacy) server type first. Plans start at 6 GB, see plans.