Valheim dedicated servers: worlds, mods and crossplay

Valheim is unusually pleasant to self-host: the server is small, the world is two files, and nothing about it requires a database or a licence. The three things that reliably trip people up are moving an existing world, mod version discipline, and crossplay.

Moving your local world across

Your world lives in two files that must travel together:

• WorldName.db — the world itself
• WorldName.fwl — the metadata

Copy both. Taking only the .db is the single most common mistake here and it produces a server that generates a fresh world while insisting everything is fine.

On Windows they are in:

%USERPROFILE%\AppData\LocalLow\IronGate\Valheim\worlds_local\

Upload both into the server's worlds_local directory through the file manager, then set the world name in the start-up parameters to match the filename without an extension. Restart, and check the console: it will tell you whether it loaded your world or generated a new one.

Characters do not need moving. Valheim keeps them client-side, so everyone brings their own.

Mods, and the version rule

Valheim modding runs on BepInEx, which is a one-click install on our Valheim plans. The rule that matters:

Every mod that changes gameplay must be installed on the server and on every client, at the same version.

Get that wrong and players either cannot connect or — worse — connect and desync quietly, which looks like the server being broken rather than a mod mismatch.

Practically:

1. Install BepInEx first, restart, confirm it loaded in the console.
2. Add mods one at a time, restarting between each. It is slower and it means you know exactly which one broke things.
3. Publish the exact mod list with version numbers somewhere your players will read it. A pinned Discord message beats good intentions.

Some mods are server-only — admin tools, world modifiers, logging. Those are fine to add without touching clients. The mod's own documentation will say; if it does not, assume both.

Valheim Plus deserves a specific warning: it has forked and stalled more than once, and the version your players install from Thunderstore may not be the version you think you installed. Pin it explicitly.

Crossplay

Crossplay lets Steam, Xbox and Game Pass players share a server. It is a start-up flag rather than a setting in game:

-crossplay

Two consequences worth knowing before you enable it:

• Crossplay servers use PlayFab networking rather than Steam's, which means the server does not appear in the Steam server browser. Players join via the in-game Join Code or by adding the address directly.
• Modded servers and crossplay do not mix well. Console players cannot install BepInEx, so a modded crossplay server either excludes them or breaks for them.

Pick one. Most communities running mods stay Steam-only; most running vanilla turn crossplay on and never think about it again.

Settings actually worth changing

Valheim's server config is short, which is refreshing. The ones that matter:

• World modifiers (combat difficulty, resource rate, raids, portals) are set in-game by an admin rather than in a config file, and they persist with the world. If you want a harder server, that is where it lives.
• -public 0 hides the server from the community browser. With a password set and the address shared privately, this is how most clan servers run.
• Save interval defaults to 20 minutes. On a busy server, shortening it costs almost nothing and reduces how much a crash can undo.

Backups matter more here than most games

A Valheim world is months of accumulated building and it is a single file that can corrupt. Nightly off-node backups with fourteen-day retention are included on every plan, and you can take a manual snapshot before doing anything risky — installing a mod, changing world modifiers, or letting someone test something.

Two clicks to restore. It is the sort of thing you never need until the one evening you very much do.

The bit people forget

Valheim's server keeps running when nobody is online — that is the whole reason to have one. Crops grow, portals stay linked, and raids can happen to an empty base. If you are coming from hosting locally, that changes how your world behaves, mostly for the better.