Valheim Server Configuration Guide

This article covers the configuration options you've got on a Valheim dedicated server, what each one actually does, and how to set them on a LOW.MS server. It's the long-form reference – if you just want a recommended setting profile, the best server settings blog has those. If you are not with us yet, our Valheim server hosting plans put every option below in the panel.

The basics

These are the options you'll want sorted on day one. Valheim takes all of them as launch arguments rather than reading them out of a config file, so on a LOW.MS server they're text boxes on the Commandline Manager page and we build the launch line around them.

Server Name

What appears in the in-game server browser. Pick something descriptive so your friends can spot it. Set internally via the -name launch parameter.

Server Password

The password players need to enter to join. Two rules to know:

• Five characters minimum. That's Valheim's own floor. Our panel asks for eight, so eight is the number that actually applies to you.
• The password can't appear inside the world name or the seed name. Note which way round that runs. It's not that the password can't contain the world name, it's that the password can't be a substring of either one. World called Midgard, password gard? Rejected. This catches people out a lot, and the seed name half of it catches out even more people because most of us never look at it.

It isn't quiet about the failure, at least. The server writes Error bad password: to the log and then exits, so if your server dies within seconds of a password change, open Log Viewer and look for that line.

Set internally via -password.

World Name

The save file the server loads. Change this and the server will load a different world (or create a new one with that name). Your old world is still there – switch the name back any time and you're back on it. Set internally via -world.

Server Port

LOW.MS assigns this automatically – you don't pick it. Valheim ports on our network start at 27515 and go up in steps of five, so yours might be 27515, 27520, 27525 and so on. Valheim always uses two consecutive UDP ports (the launch port and port+1), so a server on 27515 also occupies 27516. Those two are the only ports it needs.

If you're self-hosting at home, the default port is 2456 and you'd need to forward UDP 2456-2457 on your router.

World modifiers

World modifiers arrived with Hildir's Request in August 2023 and have been tweaked since. They adjust how the world plays, and while they're offered at world creation you can change most of them later from the in-game world menu, or set them on the server's launch line.

The five categories Iron Gate ships are:

• Combat – veryeasy, easy, normal (default), hard, veryhard
• DeathPenalty – casual, veryeasy, easy, normal (default), hard, hardcore
• Resources – muchless, less, normal (default), more, muchmore, most
• Raids – none, muchless, less, normal (default), more, muchmore
• Portals – casual, hard (default), veryhard

Combat

Adjusts how hard enemies hit and how durable you are. Hard and Very Hard make enemies hit noticeably harder and reduce player damage; Easy and Very Easy go the other way. Iron Gate has not published exact percentage tables for these, so I'd rather not invent numbers – community data-mining is on the wiki if you want the unofficial values.

Death penalty

Controls what happens when you die.

• Casual – no skill loss.
• Easy / Very Easy – reduced skill loss.
• Normal – Valheim's default.
• Hard – increased skill loss.
• Hardcore – permanent loss of all items and skills on death. Brutal.

Portal restrictions

The most argued-over setting in Valheim.

• Casual – everything goes through portals, ores included.
• Hard (default) – ores and metals can't be portalled. The vanilla experience.
• Very Hard – no items go through at all. You still travel, your inventory doesn't.

Worth being precise here, because these two things get conflated constantly: the Portals modifier only controls what you can carry through. None of its values switch portals off. Disabling portals outright is a separate global key, covered further down under admin commands.

Resource rate

Adjusts how generous resource nodes are when you mine, chop or pick.

• Much Less / Less – slower, more survival-focused.
• Normal – default.
• More / Much More / Most – for groups who'd rather build than grind.

Raid frequency

How often the game throws raid events at your bases.

• None – no raids.
• Less / Much Less – occasional raids.
• Normal – default cadence.
• More / Much More – frequent raids.

Setting modifiers on a LOW.MS server

Open Commandline Manager and switch your service to the Additional Configuration line. That line gives you two boxes the other lines don't have:

• Preset – one of Iron Gate's bundled presets: Normal, Casual, Easy, Hard, Hardcore, Immersive or Hammer. Treat this as required rather than optional. The launch line is built as -preset <your value>, so leaving the box empty produces a bare -preset with nothing after it.
• addcmd – anything else you want on the line, written out in full. Individual modifiers go here as -modifier <name> <value>, chained as many times as you like:

-modifier raids none -modifier deathpenalty casual -modifier portals casual

The most common mistake on this box by a distance is typing just raids none without the -modifier in front of it. The server starts fine, the setting does nothing, and you spend an evening wondering why raids are still turning up.

Player limit

Valheim's official cap is 10 players per server. The 10-cap is a deliberate Iron Gate design choice – Valheim's networking does some peer-to-peer lifting that doesn't scale well past that. Mods like Azumatt/MaxPlayerCount can lift the cap, but expect performance issues and the occasional weird sync bug if you do. Installing it goes through the mod installation process like any other mod, since we block customer .dll uploads.

Crossplay

There is no crossplay tick box, and if you've been sent here looking for one, that's why you couldn't find it. Crossplay is a different launch line, chosen in Commandline Manager. Three lines are available on a Valheim service:

• Default – Steam backend. World name and password boxes.
• Default (With Crossplay) – adds -crossplay, which points the server's networking at Iron Gate's PlayFab backend so players on other platforms can join.
• Additional Configuration – Steam backend, plus the Preset and addcmd boxes covered above.

Read that list twice, because the trap is in what each line doesn't have. The crossplay line has no Preset or addcmd boxes, and the Additional Configuration line has no -crossplay. They're a fork, not a toggle. Switch from one to the other and whatever the previous line owned quietly disappears from the launch line: tune your difficulty on Additional Configuration, then switch to the crossplay line so a friend on console can join, and your modifiers go with it. Nothing warns you.

No predefined line gives you both. If you need crossplay and world modifiers on the same server, open a ticket and we'll put a custom command line on the service.

Two more things worth knowing about that page:

• -public 1 is baked into all three lines. Keeping your server off the community browser is a ticket as well.
• Crossplay does not stop BepInEx loading. You'll see this claimed a lot and it isn't true. BepInEx hooks in when the game's runtime starts, before Valheim has read a single launch argument, so a flag can't switch it off. What crossplay actually breaks is individual mods that assume every player is on Steam, anything keying off SteamID64 or Steam networking. That, plus console players not being able to install mods at all, is the real reason to leave crossplay off a heavily modded server.

Server launch parameters

You don't type these directly on a LOW.MS server – we build the launch line and you fill in the boxes described above – but it's useful to know what each one is doing. These are the parameters Iron Gate documents:

You can chain -modifier multiple times to set several at once.

One of those is worth knowing the value of. We point -savedir at the Valheim folder inside your service directory, which means your world files end up one level further down again, in Valheim\worlds_local. There's no worlds_local at the top level of your service, so if you go looking for a save and can't find one, that's why.

Admin commands

Once you've added yourself to adminlist.txt and restarted the server, the in-game console (press F5) gives you the basic admin command set. The commands that work on a vanilla dedicated server are:

kick, ban, unban, banned and save are the admin set proper. Your client hands them to the server, which checks your ID against adminlist.txt before doing anything; if you're not on the list you get "You are not admin" back and nothing happens. save is worth knowing about: it forces an immediate world save and restarts the interval timer, which is the thing to run before you go poking at anything risky.

lodbias is the odd one out and worth calling out because other sites list it as a server setting. It isn't. It changes the rendering quality on your own machine and does nothing to the server at all.

One command you will see in other people's dedicated-server lists that genuinely doesn't work: noportals. It exists, but Valheim marks it host-only, so it runs in single-player and on a locally-hosted game and answers "not valid in the current context" when you're connected to a dedicated server.

Turning portals off on a dedicated server is a launch argument instead. -setkey NoPortals sets the same global key the command would have set, and portal use is then blocked for everyone. It isn't one of the four keys Iron Gate documents, but it behaves identically. On our panel the extra-arguments box only exists on the Additional Configuration command line, so if you're already on that line you can add it yourself; if you're on Default or the crossplay line, open a ticket rather than switching lines and losing the rest of your setup.

Don't reach for the Portals world modifier for this. As above, it governs what you can carry through a portal and nothing else, so no value of it will turn portals off.

A note on the cheat commands: Iron Gate intentionally restricts vanilla devcommands (god mode, fly, exploremap, spawn, etc.) to single-player and locally-hosted games. They do not work on a dedicated server out of the box, and toggling devcommands on a client connected to one won't change that. If you want them, install the Server devcommands mod by Jere Kuusela, which re-enables the full set for admins on a dedicated server.

For the full vanilla command list see the Valheim Admin Commands article.

Permissions: adminlist, bannedlist, permittedlist

Valheim manages permissions through three text files. On a LOW.MS server they sit in the Valheim folder inside your service directory, alongside worlds_local, and the place to edit them is Configuration Files, not File Manager. The panel keeps its own copy of each list and rewrites the file from that copy, so an edit made by hand in File Manager can be overwritten the next time a config is saved.

adminlist.txt

Steam64 IDs of players who should have admin access. One ID per line:

76561198012345678
76561198087654321

Restart the server after editing for changes to take effect. Full walkthrough: Valheim adminlist.txt guide.

bannedlist.txt

Steam64 IDs of banned players. Entries are added automatically when you use the ban command but you can edit the file by hand if you need to.

permittedlist.txt

If you want a whitelist-only server, add the Steam IDs of allowed players to this file. Once it has any entries, only those IDs can connect. Leave it empty for a normal password-protected server.

Backups

There are two separate things here and it's worth knowing which is which, because people tend to assume one covers the other.

Valheim's own backups. The game keeps a rolling set of world backups alongside the save, controlled by the -backups, -backupshort and -backuplong parameters above. The defaults give you 4: one short (2 hours old) and three long (12 hours apart). For most groups the defaults are fine.

Cloud Backup in the panel. Every LOW.MS service has Cloud Backup and Cloud Restore in the sidebar. Both are buttons you press – there's no automatic schedule running behind them, so if you've never opened Cloud Backup, you don't have one. Putting it on a timer is a two-minute job in Scheduled Tasks, and it's the sort of thing to sort out before you need it rather than after. Note that Cloud Restore stops the service while it runs, so don't fire it off mid-session.

Backup Manager covers the archives kept on the machine itself, which is where you'd go to pull a copy back from Valheim's own backup chain.

Performance tips

A few things that have come up in support tickets enough times that they're worth flagging up front:

• Big builds are the main lag source. Each building piece is tracked and synced. Sprawling castles with thousands of pieces will start to chug, especially when players enter the area.
• Tamed creatures count too. Each tamed animal is an active entity. A breeding farm with dozens of boars can hurt performance more than the same number of building pieces.
• Terrain modifications are sticky. Heavy use of the hoe or pickaxe on terrain creates terrain mod data that gets synced to anyone walking through. Try not to terraform every square meter of your base.
• Restart weekly. Optional, but it clears memory and resets entity states. Long-running servers benefit from a quick restart even if there's no obvious problem, and Scheduled Tasks will do it for you at whatever hour suits.

If you're seeing real performance issues, the Valheim Troubleshooting Guide walks through diagnosing them.

Need help?

Open a ticket from the panel and we'll dig in. Knowledgebase articles only go so far – if your specific server is doing something weird, support can poke at it directly.