Valheim dedicated server

SteamCMD app ID
896660
Install
steamcmd +login anonymous +app_update 896660 validate +quit
Anonymous login
yes (Anonymous DepotDownloader 3.4.0 fetch of depot 896661 succeeded, checked 2026-09-25)
OS support
Linux, macOS, Windows (server depots in SteamCMD app info)
Current build
25527701, public branch updated 2026-09-25 12:18 UTC
Install directory
Valheim dedicated server

Ports

PortProtocolPurposeSource
2456-2457 (manual) / 2456-2458 (start_server.sh)not documentedGame traffic
Valheim Dedicated Server Manual.pdf (shipped in depot)
“Valheim uses the specified Port AND specified Port+1. Default Ports are 2456-2457.”
start_server.sh comment (shipped in depot)
“NOTE: You need to make sure the ports 2456-2458 is being forwarded to your server through your local router & firewall.”

Config files

WhatPathSource
Launch settings (server name, port, world, password …)start_server.sh (Linux) / start_headless_server.bat (Windows), in the install directoryValheim Dedicated Server Manual.pdf (shipped in depot)
Worlds, adminlist.txt, bannedlist.txt, permittedlist.txt (Linux default)~/.config/unity3d/IronGate/ValheimValheim Dedicated Server Manual.pdf (shipped in depot)

Launch options (from SteamCMD app info)

OSCommand
Linuxstart_server_xterm.sh
Windowsstart_headless_server.bat
macOSstart_server.command

Settings

16 settings from Valheim Dedicated Server Manual.pdf + start_server.sh (depot 896661). Descriptions are quoted exactly; blank where the game documents none.

SettingValue in shipped start_server.shDescription
-nameMy server“Enter the name of your server that will be visible in the Server list.” — Valheim Dedicated Server Manual.pdf
“NOTE: Minimum password length is 5 characters & Password cant be in the server name.” — start_server.sh
-port2456“Choose the Port which you want the server to communicate with. Please note that this has to correspond with the Port Forwarding settings on your Router. Valheim uses the specified Port AND specified Port+1. Default Ports are 2456-2457. If you’re using the Crossplay backend (enabled using the “-crossplay” argument), you do not need to do Port Forwarding on your Router. The Port number is still used to distinguish between multiple servers on the same public IP address.” — Valheim Dedicated Server Manual.pdf
-worldDedicated“A World with the name entered will be created. You may also choose an already existing World by entering its name.” — Valheim Dedicated Server Manual.pdf
-passwordsecret“Set the password.” — Valheim Dedicated Server Manual.pdf
“NOTE: Minimum password length is 5 characters & Password cant be in the server name.” — start_server.sh
-savedirnot set“Overrides the default save path where Worlds and permission-files are stored. Default path WINDOWS: “../%USERPROFILE%/AppData/LocalLow/ IronGate/Valheim” LINUX: “~/.config/unity3d/IronGate/Valheim ”” — Valheim Dedicated Server Manual.pdf
-publicnot set“Set the visibility of your server. 1 is default and will make the server visible in the browser. Set it to 0 to make the server invisible and only joinable via the ‘Join IP’-button. Setting public to 0 is a good option if you wish to run a local LAN server, where players can join via the local IP of the server.” — Valheim Dedicated Server Manual.pdf
-logFilenot set“Sets the location to save the log file.” — Valheim Dedicated Server Manual.pdf
-saveintervalnot set“Change how often the world will save in seconds. Default is 30 minutes (1800 seconds).” — Valheim Dedicated Server Manual.pdf
-backupsnot set“Sets how many automatic backups will be kept. The first is the ‘short’ backup length, and the rest are the ‘long’ backup length. By default that means one backup that is 2 hours old, and 3 backups that are 12 hours apart.” — Valheim Dedicated Server Manual.pdf
-backupshortnot set“Sets the interval between the first automatic backups. Default is 2 hours (7200 seconds).” — Valheim Dedicated Server Manual.pdf
-backuplongnot set“Sets the interval between the subsequent automatic backups. Default is 12 hours (43200 seconds).” — Valheim Dedicated Server Manual.pdf
-crossplay(flag set)“Runs the Server on the Crossplay backend (PlayFab), which lets users from any platform join. If you do not include this argument, the Steam backend is used, which means only Steam users can see and join the Server.” — Valheim Dedicated Server Manual.pdf
-instanceidnot set“If you’re hosting multiple servers with the same port from the same MAC address, write something unique here for each server to ensure that they get unique PlayFab IDs.” — Valheim Dedicated Server Manual.pdf
-presetnot set“Sets world modifier preset. Setting a preset will overwrite any other previous modifiers. Valid values are: Normal, Casual, Easy, Hard, Hardcore, Immersive, Hammer.” — Valheim Dedicated Server Manual.pdf
-modifiernot set“Sets chosen world modifier with value. If combined with a preset should be set after. Valid modifiers and values are: Combat : veryeasy, easy, hard, veryhard DeathPenalty : casual, veryeasy, easy, hard, hardcore Resources : muchless, less, more, muchmore, most Raids : none, muchless, less, more, muchmore Portals : casual, hard, veryhard” — Valheim Dedicated Server Manual.pdf
-setkeynot set“Sets a world modifier checkbox key. Valid values are: nobuildcost, playerevents, passivemobs, nomap” — Valheim Dedicated Server Manual.pdf

Changed in the last server update

Tracking began with build 25527701. No earlier build's files have been recorded yet, so there is nothing to compare.