How to Host a Valheim Dedicated Server: Setup, Parameters and Mods
Quick answer
To host Valheim, download the dedicated server with SteamCMD (app ID 896660) and run it from the start script with -name, -port, -world, -password and -public. The password must be at least 5 characters and must not appear in the server name. The server uses UDP 2456 and 2457 by default and holds up to 10 players. Add -crossplay for console and Game Pass players, set the world rules with -preset and -modifier, and back up the worlds_local folder regularly.
What do you need to host a Valheim server?
The Valheim dedicated server is a separate program that Iron Gate distributes for free. It runs on Windows and Linux, installs through SteamCMD under app ID 896660 and does not require you to own the game. Valheim has no server config file: the server name, world, password and difficulty are all set as parameters in the start script.
Valheim is modest on hardware, but one design choice is worth knowing. The game hands the physics and creature simulation for each area of the world to the computer of the first player who enters it. So while single-thread CPU performance and a good connection matter on the server, a player on a weak connection can also cause lag for everyone near them. A vanilla server takes up to 10 players; going beyond that needs a mod.
- SteamCMD and Valheim Dedicated Server, app ID 896660
- Game ports: UDP 2456 and 2457 (the port and the one above it)
- A password of at least 5 characters that is not part of the server name
- 4 GB of RAM for a small group, 8 GB for a full or modded server
- Your SteamID64 so you can make yourself an admin
How do you install a Valheim dedicated server with SteamCMD?
Install SteamCMD, pick an empty folder with force_install_dir, log in with login anonymous and run app_update 896660 validate. When the download finishes, the folder contains a start script: start_headless_server.bat on Windows and start_server.sh on Linux. Instead of editing these directly, make a copy under your own name, because updates can overwrite the originals.
The script launches the valheim_server executable with -nographics and -batchmode, followed by your server parameters. When you stop the server, use Ctrl+C rather than killing the window. Valheim saves the world on a clean shutdown, and a hard kill throws away everything since the last autosave.
Hosting on your own PC works, but the world goes offline when the PC does and you will need to forward ports on your router. A rented server comes with the files and script ready. In the TheCrewHost game panel Valheim installs with one click, and you change the parameters through form fields instead of editing a script.
What do the Valheim launch parameters do?
The most common mistake is the password rule. It must be at least 5 characters long and must not be contained in the server name. Break the rule and the server either refuses to start or nobody can connect. Wrap any value with spaces in quotes, and keep the world name short and free of special characters.
The -world parameter decides which world loads. If no world with that name exists, the server creates a new one. Calling an existing world by a slightly different name is an easy way to start a blank world by accident, so type the name exactly as the file is named.
Valheim's own backup chain is also set through parameters. The defaults suit most servers, but you should still copy the world off the server on a schedule of your own.
| Parameter | What it does | Note |
|---|---|---|
| -name | Name shown in the server list | Must not contain the password |
| -port | Game port | Default 2456; the next port is used too |
| -world | Name of the world to load | Creates a new world if none exists |
| -password | Join password | At least 5 characters |
| -public | Server list visibility | 1 listed, 0 hidden |
| -crossplay | Xbox, Game Pass and other platforms | Without it only Steam players can join |
| -savedir | Folder for worlds and list files | Makes backups easier |
| -saveinterval | Autosave interval in seconds | Default 1800 |
| -backups / -backupshort / -backuplong | Number and spacing of backups | Default is 4 backups |
| -preset / -modifier / -setkey | World difficulty and rules | See the next section |
How do you change world settings with -preset and -modifier?
The world modifiers screen from single player maps onto three server parameters. -preset picks a ready-made profile: normal, casual, easy, hard, hardcore, immersive and hammer. Hammer suits groups who want to build without enemies or raids, while immersive restricts the map and portals for a more grounded experience.
-modifier tunes a single setting and takes a type followed by a value. For example, -modifier combat hard makes enemies tougher, -modifier deathpenalty casual softens death, -modifier resources more boosts gathering, -modifier raids none turns raids off and -modifier portals casual lets metals through portals. -setkey adds on or off switches such as nobuildcost, playerevents, passivemobs and nomap.
These settings apply to everyone who joins and are stored with the world. You can change them mid-game, but tell your community first. Making death harsher or switching off the map changes the game people are used to in a big way.
Which ports does a Valheim server use?
Valheim uses the port you set with -port plus the one above it, which by default means UDP 2456 and 2457. Some guides open 2456-2458 to stay on the safe side. On a home connection, forward those ports on your router to the server's local IP and allow them through the firewall. If you run a second server on the same machine, start it on a port range that does not overlap, such as 2466.
With -crossplay enabled, connections go through the PlayFab backend and players can also join with a join code. Port forwarding problems show up less often in that mode, but keeping the ports open is still good practice for list visibility and direct IP joins.
How do players join a Valheim server?
A server started with -public 1 can be found by name in the Community tab of the Join Game screen. To connect directly, players click Join IP on the same screen and type IP:port, for example 203.0.113.10:2456. Steam players can also add the server to their Steam favourites using the query port, which is the game port plus one.
With -crossplay on, the server writes a join code to its log when it starts. Console and Game Pass players typically join with that code or through the list. The code can change after a restart, so keep the current one somewhere like your Discord. A server without crossplay accepts Steam players only. If joining fails, first check that the game and server versions match.
Where are the world files and how do you back them up?
Worlds live in the worlds_local folder: %USERPROFILE%\AppData\LocalLow\IronGate\Valheim\worlds_local on Windows and ~/.config/unity3d/IronGate/Valheim/worlds_local on Linux, or under the folder you passed to -savedir. Each world is two files: the .db holds the world itself and the .fwl holds its name and seed. Always copy them together.
Valheim keeps its own rolling backups, but they sit on the same disk. A solid routine adds a daily copy of the .db and .fwl files to another location, taken while the server is stopped or right after a save. Take a manual backup before a big update or before adding mods.
Moving a single-player world, or one a friend has been hosting, onto the server is just as simple: put the same two files in the server's worlds_local folder. The only rule is that -world must match the file name exactly.
How do you manage admins and bans?
Next to worlds_local in the save folder you will find three text files: adminlist.txt, bannedlist.txt and permittedlist.txt. Each line holds one player ID, which for Steam players is their SteamID64. Players who join through crossplay have IDs with a platform prefix, and the simplest approach is to copy the ID exactly as it appears in the server log. Restart the server after editing.
When permittedlist.txt has entries, only the listed players can join, which makes a handy extra lock on a private server alongside the password. Admins open the console in game with F5 and can use commands such as kick, ban, unban, banned and save. Cheat commands are not available on a dedicated server, even to admins; to change world rules, use the -setkey and -modifier parameters instead.
How do you install BepInEx and Valheim Plus mods?
Almost every Valheim mod runs on top of the BepInEx mod loader. You install the BepInEx pack built for Valheim on the server, then drop each mod's .dll into the BepInEx/plugins folder. Most mods also need to be installed on every player's PC at the same version; if versions do not match, players fail to connect or see odd errors. Mod managers make it easy to share a profile so everyone runs the same list.
Valheim Plus is a large mod that gathers dozens of tweaks, including player limits, stack sizes, building and inventory, into one config file. The original project went long stretches without updates and has been carried on by community forks, so make sure a version compatible with the current game exists before you install it. Valheim left early access with its 1.0 release in 2026, and big updates usually break most mods for a while. When an update lands, back up first, wait for your mods to catch up, then update the server.
| Players | Suggested RAM | CPU note |
|---|---|---|
| 1-3 | 2-4 GB | Any modern core is fine |
| 4-6 | 4-6 GB | Strong single-thread performance helps |
| 7-10 | 6-8 GB | Large bases lengthen save times |
| Modded, or above 10 with a mod | 8 GB or more | Scales with the number of mods |
Set up your Valheim server in 7 steps
- 1
Download the server files
Log in anonymously with SteamCMD and run app_update 896660 validate into an empty folder, or rent a server with Valheim preinstalled.
- 2
Copy the start script
Make a copy of start_headless_server.bat or start_server.sh so updates do not overwrite your settings.
- 3
Fill in the basic parameters
Set -name, -port, -world, -password and -public, making sure the password is at least 5 characters and does not appear in the server name.
- 4
Choose crossplay and world rules
Add -crossplay for console and Game Pass players, and set the difficulty with -preset or individual -modifier values.
- 5
Open the ports
Allow UDP 2456 and 2457 through the firewall and forward them on your router if you host at home.
- 6
Make yourself an admin
Add your SteamID64 to adminlist.txt, restart the server and try a few commands in the F5 console.
- 7
Set up backups
Copy the .db and .fwl files from worlds_local off the server every day and take a manual backup before each update.
Frequently Asked Questions
How many players can a Valheim server hold?
A vanilla server is capped at 10 players, and no launch parameter raises it. For a bigger server you need a mod that changes the limit; check whether every player will need it installed too. Raising the cap loads the players' PCs as well as the server, because the simulation of each area runs on a player's machine.
The server starts but nobody can connect. Why?
The usual suspects are a password shorter than 5 characters or one that appears in the server name, closed ports, and a mismatch between the game and server versions. Look for an error line in the server log, then check the ports and version. If crossplay is on, make sure players are using the current join code.
Can I take the server world back to my own PC?
Yes. Stop the server, download the .db and .fwl files from worlds_local and put them in the same folder on your PC. The world then shows up in single player. The reverse works the same way. Backing up the files on both sides before you move anything is the simplest guard against overwriting the wrong copy.
Are there downsides to enabling crossplay?
Crossplay routes connections through PlayFab and lets console and Game Pass players in. Some players notice slightly different ping in that mode, and a few mods do not play well with it. If your group is all on Steam you do not need it; for a mixed group it is the only option.
Valheim just updated. How do I update my server?
Shut the server down cleanly with Ctrl+C, back up the world files and run app_update 896660 validate in SteamCMD again. On a modded server, first check that your mods have been updated for the new version. An incompatible mod can stop the server from starting or keep players from connecting.
Why does the server's RAM use grow over time?
As players explore and build, the world file grows and the server tracks more objects. Large bases and piles of dropped items increase both memory use and save times. Regular restarts, removing mods you do not need and clearing items left on the ground slow that growth. If it keeps happening, moving to a plan with more RAM is the cleanest fix.
Valheim Plus or individual mods?
Valheim Plus is convenient because it bundles many tweaks, but that breadth also raises the risk of breaking after updates. If you only want a few features, small BepInEx mods that each do one thing tend to be updated faster. Whichever route you pick, make sure every player runs the same mod list and versions.
