Valheim Dedicated Server Setup: Launch Parameters, Ports and Saves
A Valheim dedicated server needs four things on its launch line: -name, -port (2456 by default), -world and -password. Everything else is optional. The password must be at least five characters and must not contain the world name or server name, or the server refuses to start.
This guide covers the official launch parameters, how players connect (Steam IP connect versus crossplay join codes), where world data lives and how backups work. Details were checked against Iron Gate's official dedicated server guide and community documentation on 2026-11-01, after the Valheim 1.0 release on 9 September 2026.
- Minimum launch line:
-nographics -batchmode -name "My Server" -port 2456 -world "Midgard" -password "secret123". - The default game port is UDP 2456, and the next port up (2457) is used as well. With
-crossplayenabled you do not need to forward ports. - Password rules: at least 5 characters, and it cannot contain the world name or server name.
- A world is saved every 30 minutes by default (
-saveinterval 1800), with 4 automatic backups kept (-backups 4). - Client and server versions must match, so update the server before players update.
On this page
- The minimum launch command
- All the launch parameters worth knowing
- Ports, crossplay and how players connect
- Password and name rules that stop servers from starting
- Where world data lives, and how saving and backups work
- Admin, ban and permitted lists
- Valheim 1.0 notes for server owners
- Frequently asked questions
- References
The minimum launch command
The server is installed as the free “Valheim Dedicated Server” tool in Steam (enable the Tools filter in your library). Iron Gate's guide tells you to edit the launch parameters in the start script it ships, start_headless_server.bat on Windows or start_server.sh on Linux. Steam resets that file on every update, so edit a copy instead and launch the copy yourself.
valheim_server.exe -nographics -batchmode -name "My Server" -port 2456 -world "Midgard" -password "secret123" -public 1Wait for the console to print Game server connected before telling players to join. To stop the server, press CTRL+C in the window; closing it with the X can leave the process running in the background.
All the launch parameters worth knowing
| Parameter | What it does | Default |
|---|---|---|
-name "text" | Server name shown in the server list. | none |
-port 2456 | Game port. The server also uses the next port up. | 2456 |
-world "name" | World to load. Creates a new world if that name does not exist. | none |
-password "text" | Join password. | none |
-savedir PATH | Overrides where worlds and the admin/ban/permitted lists are stored. | user profile folder |
-public 1 | Lists the server in the community browser; 0 hides it. | 1 |
-logFile PATH | Writes the log to a file. | none |
-saveinterval 1800 | Seconds between world saves. | 1800 |
-backups 4 | Number of automatic backups kept. | 4 |
-backupshort 7200 / -backuplong 43200 | Intervals (seconds) for the short and long automatic backups. | 7200 / 43200 |
-crossplay | Uses the PlayFab backend so players on any platform can join. | off |
-instanceid "1" | Unique ID when running several servers on one address and port. | none |
-preset, -modifier, -setkey | World modifiers: presets such as normal, casual, easy, hard, hardcore, immersive and hammer; -modifier raids none; -setkey nomap. | normal |
Ports, crossplay and how players connect
There are two networking backends, and which one you pick decides how players join.
- Steam backend (default). Forward UDP 2456-2457 on your router and firewall. Players join through the in-game Community server list, or choose Join IP and enter the address and port plus the password.
- Crossplay backend (
-crossplay). Uses PlayFab, so no port forwarding is needed. Players can connect by public IP and port, by join code, or from the server list. Loopback and local addresses do not work. Since 1.0, console players join with a code shown in the server console.
On Linux the crossplay backend needs extra libraries; the official guide lists libatomic1, libpulse-dev and libpulse0. If your Linux release is older than GLIBC 2.29 or GLIBCXX 3.4.26, run the server in Docker with the script Iron Gate provides.
If you use a hosting provider you generally do not forward ports or edit batch files yourself. Hosting with ChicagoServers? The Valheim server hosting page lists what is included, such as a one-click BepInEx installer, free server backups and SFTP file access.
Password and name rules that stop servers from starting
- The password must be at least five characters.
- It cannot contain the server name or the world name. Community docs and host guides all report the server failing to start when it does.
- Use quotes around names or passwords containing spaces.
- The Steam server browser's password box is not read by the game. Enter the password in Valheim's own dialog.
Where world data lives, and how saving and backups work
Before 1.0, a world is two files named after it: Midgard.db (the world's progress) and Midgard.fwl (metadata including the seed). You need both to back up or move a world. Default locations are %USERPROFILE%\AppData\LocalLow\IronGate\Valheim on Windows and ~/.config/unity3d/IronGate/Valheim on Linux; -savedir overrides them. Worlds sit in a worlds_local subfolder.
With 1.0, each world is stored as a folder named after the world, holding numbered .fwl2, .db2 and chunk files. Older worlds load and are converted the first time they are saved. Conversion is effectively one-way, so keep your own copy of the original .db and .fwl before the first 1.0 load.
- Automatic saves: every 1800 seconds unless you change
-saveinterval. - Automatic backups: controlled by
-backups,-backupshortand-backuplong. They sit on the same disk as the world, so they are not a substitute for an off-machine copy. - Manual backup: stop the server, then copy the whole world (both old-style files, or the entire 1.0 folder).
Admin, ban and permitted lists
Three text files live in the save folder (or -savedir): adminlist.txt, bannedlist.txt and permittedlist.txt. Put one platform user ID per line in the format [Platform]_[UserID], which is case-sensitive. Valheim shows IDs in the server log and in the in-game F2 panel. Admins can open the F5 console and use kick, ban, unban and banned.
Valheim 1.0 notes for server owners
- Valheim 1.0 and the Deep North update released on 9 September 2026. Host documentation reports the launch parameters above are unchanged.
- The server still supports up to ten players.
- Clients and servers must run matching builds. Update the server first, because players on 1.0 cannot join an older build.
- Existing saves stay compatible, but Deep North only generates in areas nobody has explored, so heavily explored worlds may suit a new seed better.
- Mods built for earlier versions often break on a major engine update. See the BepInEx guide before updating a modded server.
Check the current Iron Gate patch notes before relying on any version-specific detail here. Hotfixes followed the 1.0 launch.
Frequently asked questions
What ports does a Valheim dedicated server use?
The default game port is 2456, and the server also uses the next port up, 2457 (UDP). With -crossplay enabled you do not need to forward ports.
Why won't my Valheim server start with my password?
The password must be at least five characters and cannot contain the server name or the world name. Change the password or the name and restart.
How do I let console players join my Valheim server?
Start the server with the -crossplay parameter. Players then join by join code (shown in the console), by public IP and port, or from the server list. Console players cannot install mods, so only use server-side mods if consoles must join.
Where does Valheim save a dedicated server world?
In a worlds_local subfolder of the save directory: AppData\LocalLow\IronGate\Valheim on Windows, or ~/.config/unity3d/IronGate/Valheim on Linux. Use -savedir to put it somewhere else.