Moving a Valheim world to a dedicated server (the new folder save format)

We moved a world from a friend’s PC to my Docker Valheim server. Every guide I found said “copy WorldName.db and WorldName.fwl”. Those files didn’t exist. Valheim changed its save format, and here’s what it looks like now.

The new format: a folder per world

Instead of two files, each world is now a folder named after the world:

worlds_local/
└── MyWorld/
    ├── 1e_1e__1_2.chunk
    ├── 20_20__1_39.chunk
    ├── ...more .chunk files...
    ├── _main.40.chunks
    ├── _main.40.db2
    ├── _main.40.fwl2
    └── _main.40.ok

• .chunk files hold parts of the map: terrain, buildings, chests.
• _main.N.* is the world’s main data. The number N goes up with every save (40, 41, 42…).

Don’t confuse it with the map-cache files that sit next to it (cacheMinimapHeight, MyWorld_mapTexCache…). Those only store how the minimap looks. Our first attempt sent exactly those, and the world wasn’t in them.

Where to find it on Windows

Local worlds: press Win + R and paste:

%USERPROFILE%\AppData\LocalLow\IronGate\Valheim\worlds_local

Steam Cloud worlds live in Steam’s folder instead:

C:\Program Files (x86)\Steam\userdata\<your-id>\892970\remote\worlds

892970 is Valheim’s app ID. <your-id> is the same number as your Steam friend code (Friends → Add a Friend).

Easiest option for cloud saves: Steam lets you download your cloud files in a browser at https://store.steampowered.com/account/remotestorageapp/?appid=892970. Or, in-game: Start Game → select the world → Move to local.

Who has the world? Whoever hosted the game. The other players only have map caches.

Loading it on the server

1. Zip the whole world folder and copy it to the server.
2. Stop the server so it can’t overwrite anything: docker compose stop.
3. Put the folder in the server’s world directory:

   ./config/worlds_local/MyWorld/

4. Set WORLD_NAME=MyWorld (the folder name, exactly) and start it again.

The log should show it loading the existing save, not creating a new world:

ZNet.LoadWorld: MyWorld (MyWorld), save number 40
ConnectPortals => Connected 5 portals.

If you see missing ... MyWorld.db and a fresh world, the name or path is wrong.

World modifiers come along

The _main.N.fwl2 file stores the world’s settings: seed, world modifiers and the list of players who’ve joined. Running strings on it shows things like resourcerate 300 and deathpenalty_veryeasy. Anything you set with -modifier on the server applies on top.

Tip: everyone switches at the same time

Once the world is on the server, nobody should keep playing their local copy. The two copies split apart immediately, and there’s no merging them.