Valheim server settings don’t live in a config file. They’re start parameters on the server’s launch line: -name, -world, -password, -public and -port, plus -preset, -modifier and -setkey for world modifiers and -saveinterval and -backups for saving. The only real files are adminlist.txt, bannedlist.txt and permittedlist.txt. Below is every setting, its default, and how to change it on Windows, Linux, Docker or a hosted server.
Where is the Valheim server config file?
There isn’t a configuration file in the usual sense. A vanilla Valheim dedicated server reads its settings from the launch line in start_headless_server.bat on Windows or start_server.sh on Linux, both in the server’s install folder. Edit a copy of that script, because Steam overwrites the original on every update. Player permissions are the exception: they live in three text files in the save folder.
| File | What it holds | Where it is |
|---|---|---|
start_headless_server.bat (Windows) / start_server.sh (Linux) |
The launch line, with every server setting | Server install folder (in Steam: Manage → Browse local files) |
adminlist.txt, bannedlist.txt, permittedlist.txt |
Admins, bans, whitelist | Save folder: %USERPROFILE%\AppData\LocalLow\IronGate\Valheim or ~/.config/unity3d/IronGate/Valheim, unless -savedir moves it |
worlds_local/ |
Your worlds and their backups | Inside the save folder |
BepInEx/config/*.cfg |
Mod settings, on modded servers only | Server install folder |
| Docker environment variables | SERVER_NAME, WORLD_NAME, SERVER_PASS, SERVER_PUBLIC, CROSSPLAY, and SERVER_ARGS for anything else |
Your docker run line or compose file |
The install folder also holds Valheim Dedicated Server Manual.pdf, Iron Gate’s own copy of the reference below. New to running a server? Start with the Valheim dedicated server guide.
Every Valheim server setting (start parameters)
These are all the start parameters Iron Gate documents for the dedicated server, with their defaults. Add them to the launch line after valheim_server.exe or ./valheim_server.x86_64, put quotes around anything with spaces, and restart the server for a change to apply. Leave -nographics -batchmode in place: they’re part of Iron Gate’s example line for a server with no window.
| Parameter | Default | What it does |
|---|---|---|
-name "My server" |
none | The server name shown in the server list |
-world "Dedicated" |
none | Loads the world with this name, or creates it if it doesn’t exist |
-password "Secret" |
none | Join password: at least 5 characters, not part of the server name |
-port 2456 |
2456 | Game port. The server also uses the next port, so the default range is UDP 2456–2457 |
-public 1 |
1 | 1 lists the server in the Community list; 0 hides it so players join with Join IP |
-crossplay |
off | Runs on the Crossplay (PlayFab) backend so any platform can join; no port forwarding needed |
-savedir "path" |
see table above | Moves the folder where worlds and the three list files are stored |
-logFile "path" |
none | Writes the server log to a file |
-saveinterval 1800 |
1800 (30 min) | Seconds between world saves |
-backups 4 |
4 | How many automatic backups to keep |
-backupshort 7200 |
7200 (2 h) | Interval for the first, “short” backup |
-backuplong 43200 |
43200 (12 h) | Interval between the remaining backups |
-preset hard |
none | World modifier preset (values below). Overwrites any modifier set before it |
-modifier raids none |
none | Sets one world modifier to a value |
-setkey nomap |
none | Turns on a checkbox modifier |
-resetmodifiers |
off | Resets the world modifiers (added in patch 0.217.22) |
-instanceid "1" |
none | A unique value per server when you run several crossplay servers on the same port and machine, so each gets its own PlayFab ID |
Valheim server name and password rules
The name is what players see in the Community list; the password is what they type to get in. Valheim’s own start script spells out the rules: the password needs at least 5 characters and can’t be part of the server name. A shorter password stops the server from starting at all, so if a new server closes right after launch, check the password before anything else.
- Changing the Valheim server password: edit
-password, restart, and give your group the new one. Nobody’s character or the world is affected. - Renaming the server: change
-nameonly. Changing-worldinstead points the server at a different world, and a name that doesn’t exist yet creates a brand-new one. - No password at all? Vanilla has no switch for it. For LAN games, the Docker project documents the ValheimPlus mod’s
disableServerPasswordoption, which works without players installing ValheimPlus.
How to make a private Valheim server
A Valheim private server takes three settings: -public 0 so it’s hidden from the Community list, a password only your group knows, and, if you want it locked down, a whitelist in permittedlist.txt so nobody else gets in even with the password. Players then join with Join IP and your address. For a LAN-only server, -public 0 plus the server’s local IP is enough.
- Set
-public 0and a strong-passwordon the launch line. - Optional whitelist: put each player’s ID in
permittedlist.txt, one per line. The moment one ID is in it, everyone else is blocked, including you if you forget yourself. - Restart and share the address (public IP and port, for example
203.0.113.25:2456) with your group.
World modifiers on a dedicated server
World modifiers change how hard the world is: combat, death penalty, resources, raids and portals, plus switches like no map or passive enemies. On a dedicated server you set them with -preset, -modifier and -setkey on the launch line, or as an admin from the F5 console. Put a preset first and single modifiers after it, because a preset overwrites anything set before it.
Presets (-preset): Normal, Casual, Easy, Hard, Hardcore, Immersive, Hammer. Hammer mode lets you build without material costs; in 1.0 it counts as a temporary cheat and blocks some achievements while it’s on.
Modifier (-modifier) |
Values | What changes |
|---|---|---|
combat |
veryeasy, easy, hard, veryhard |
Damage both ways. Very hard: you deal 70% and enemies 200%. Very easy: 125% and 50% |
deathpenalty |
casual, veryeasy, easy, hard, hardcore |
Casual keeps equipped gear and costs 1% of skills. Hard destroys the unequipped inventory. Hardcore destroys everything you carry and resets all skills |
resources |
muchless, less, more, muchmore, most |
Drop rates: 0.5×, 0.75×, 1.5×, 2× and 3× |
raids |
none, muchless, less, more, muchmore |
How often base raids happen |
portals |
casual, hard, veryhard |
Casual loosens the portal rules, hard and veryhard tighten them. The game’s menu offers “portal items” (everything goes through), “no boss portals” and “no portals” |
Checkbox keys (-setkey): nobuildcost (building is free), playerevents (raids follow each player’s own progress, kinder to groups at different stages), passivemobs (enemies don’t attack until provoked) and nomap (no map or minimap).
-preset hard -modifier raids muchless -modifier deathpenalty casualChanging them later. As an admin in the F5 console: setworldpreset hard, setworldmodifier raids none, or resetworldkeys to put modifiers back to default without touching boss progress. One quirk: you can’t set a single modifier back to normal with setworldmodifier; reset or pick a preset instead. The admin commands are covered in Valheim server commands.
Save and backup settings
Valheim saves the world every 30 minutes by default and keeps four automatic backups: one about 2 hours old and three 12 hours apart. Change that with -saveinterval, -backups, -backupshort and -backuplong, all in seconds except the count. Since 1.0 the world is saved in chunks, only changed chunks are rewritten, and each backup gets its own folder, so saving is faster than it was.
-saveinterval 900 -backups 6 -backupshort 3600 -backuplong 21600That saves every 15 minutes and keeps six backups, the first an hour old and the rest six hours apart. Shorter intervals mean less progress lost after a crash. Each backup takes disk space, though, and big worlds have big backups.
Admin, ban and whitelist files
Three text files control who can do what: adminlist.txt for admins, bannedlist.txt for bans and permittedlist.txt for a whitelist. They sit in the save folder, one player ID per line, in the format [Platform]_[User ID], copied exactly from the F2 panel in game or from the server log. IDs are case sensitive, and a stray space or comment on a line breaks it.
// List admin players ID ONE per line
Steam_76561198000000000Replace the example with your own ID from the F2 panel. Admin rights cover kicking, banning, saving and world modifiers, not cheats.
How to change Valheim server settings
Stop the server, edit the launch line in your copy of the start script (or the Docker environment variables), save the file and start the server again. Valheim reads start parameters only at launch, so nothing changes until the restart. World modifiers are the one setting an admin can also change on a running world, from the F5 console, without a restart.
- Windows: stop with Ctrl+C, right-click your copy of
start_headless_server.bat, choose Edit, change the launch line, save, double-click to start. - Linux: stop with Ctrl+C or SIGTERM, edit your copy of
start_server.sh, start it again. - Docker: change the variables and recreate the container. Parameters without their own variable go in
SERVER_ARGS, for exampleSERVER_ARGS="-preset hard -saveinterval 900". - Hosted: on Valheim server hosting from GameTeam you can edit the start parameters in the panel, or describe the change and let the AI copilot make it.
Example launch lines
Here are three launch lines that cover most groups. Swap in your own name, world and password; the rest can be copied as is. Each goes after valheim_server.exe -nographics -batchmode on Windows, or ./valheim_server.x86_64 -nographics -batchmode on Linux. Restart after changing it, then check the console to confirm the world loaded under the name you expected.
Relaxed private world for friends
-name "My server" -port 2456 -world "Dedicated" -password "Secret" -public 0 -preset casualHard public world, raids based on each player’s progress
-name "My server" -port 2456 -world "Dedicated" -password "Secret" -public 1 -preset hard -setkey playereventsCrossplay world with tougher fights and fewer raids
-name "My server" -port 2456 -world "Dedicated" -password "Secret" -crossplay -modifier combat hard -modifier raids muchlessTroubleshooting Valheim server settings
When a Valheim setting doesn’t stick, it’s usually one of four things: you edited the original start script and Steam reset it, the server wasn’t restarted, a quote or dash on the launch line is wrong, or a modifier sits before -preset and the preset overwrote it. The console output right after start shows the world it loaded, which is the quickest check.
| Symptom | Likely cause | Fix |
|---|---|---|
| Settings gone after an update | You edited the original start script | Edit a copy and launch the copy |
| Server closes right after launch | Password shorter than 5 characters | Use a longer password that isn’t part of the server name |
| A modifier didn’t apply | It came before -preset |
Put the preset first, single modifiers after |
| New, empty world instead of yours | -world doesn’t match your world’s name exactly |
Use the folder name in worlds_local |
| Admin commands don’t work | ID in the wrong format, or the list file is in the wrong folder because of -savedir |
Copy the ID from F2; put the file in the folder the server actually uses |
| Docker ignores your script edits | The container builds its own launch line | Use the environment variables and SERVER_ARGS |
Skip the launch line: change settings by asking
On a hosted server you never have to touch the launch line. With Valheim server hosting on GameTeam, the built-in AI copilot edits it for you, restarts the server and reads the setting back so you can see what changed. You pay per GB of RAM, from $0.49/GB a week, with unlimited slots, and Valheim’s own 10-player limit is the only cap.
Type “make it private, hard combat, and let us keep our gear when we die” and the copilot sets -public 0, -modifier combat hard and -modifier deathpenalty casual, then restarts. Paste a friend’s ID from the F2 panel and ask it to make them admin, and it adds the line to adminlist.txt. Want mods on top? See how to add mods to a Valheim server.
FAQ
How do I change the server settings on Valheim?
Stop the server, edit the start parameters in your copy of start_headless_server.bat or start_server.sh, and start it again. World modifiers can also be changed live by an admin in the F5 console.
How do I find the Valheim server config?
Open the server’s install folder (in Steam: right-click Valheim Dedicated Server, then Manage → Browse local files). The settings are on the launch line of the start script; the admin, ban and whitelist files are in the save folder.
Does Valheim have a server?
Yes, a free dedicated server tool on Steam, plus Start Server for hosting from your own game. The dedicated server guide covers setup, ports and requirements.
Can I change world modifiers on an existing world?
Yes. Add -preset or -modifier to the launch line and restart, or use setworldpreset and setworldmodifier in the console as an admin. Your buildings and progress stay.
Does changing settings reset my world?
No. Only pointing -world at a name that doesn’t exist creates a new world, and your old one stays in worlds_local.