If you've been running your Valheim world by hitting "Start Game" and letting friends hop onto your machine, you already know the pain: the second you log off to sleep, the world dies with you. A proper Valheim dedicated server fixes that. It runs the world as its own process, independent of any player, so your friends can grind iron at 3am while you're offline and the boss you weakened stays weakened. This guide covers the parts that actually matter: passwords, crossplay, seeds, moving an existing world across, and backups that will save you when (not if) something goes sideways.
Why a persistent server beats host-and-play
The "co-op" option in the main menu is fine for one evening. It ties the world to a single person's PC and connection, though. When the host quits, everyone gets kicked, and the progress from that session lives on a home machine that's also running Discord, a browser with forty tabs, and who knows what else.
A dedicated server splits the world off from the players. It keeps simulating: portals stay linked, tamed boars keep breeding, your base defenses hold even when nobody's logged in. For a group of more than two or three people on different schedules, that's not a luxury. It's the difference between a world that grows and one that stalls out every time the "host" is busy. If you're torn between running it on your own box and letting someone else own the uptime, we went through the honest trade-offs in our breakdown of game server hosting versus self-hosting.
World and password setup
The Valheim dedicated server takes a handful of launch parameters, and getting them right the first time saves you a restart. Three matter most: the server name, the world name, and the password.
- Server name (-name): what shows in the community browser. Make it searchable if you want strangers, or obscure if you don't.
- World name (-world): the actual save on disk, stored in your worlds_local folder as a pair of files ending in .db and .fwl. Pick a name and keep it. If you already have a single-player world you love, this is the name you'll reuse to bring it across.
- Password (-password): required, at least five characters, and it cannot contain your server name. That second rule trips people up constantly. If the server refuses to boot with a vague error, check that your password isn't a substring of the server name.
Set a real password even for a private world. Valheim servers get scanned, and an open one attracts randoms who wander in and dig up your base. On a managed panel like ours you'll type these into config fields instead of a raw command line, but the same three values apply. The Valheim server hosting page shows the one-click install and where each setting lives.
Public vs community listing
The -public flag decides whether your server shows up in the in-game community list. Set it to 0 and people join by direct IP and port. The default is 2456 UDP, but it actually uses 2456 through 2458, so open all three if you're doing this behind your own router. Set it to 1 and it's listed publicly. For a friends-only world, -public 0 plus your password is the clean answer.
Crossplay so PC and Xbox can actually play together
Crossplay was one of the better things to happen to Valheim, and it's off by default on dedicated servers. Turn it on by passing -crossplay as a launch argument. Once it's enabled, the server registers with the PlayFab network and drops a "join code" into the logs: a short character string that Xbox and Microsoft Store players use to connect, since they can't join by raw IP the way Steam players can.
Two things I've learned doing this repeatedly. Crossplay servers sometimes take an extra minute to appear in the cross-platform browser after boot, so don't panic if it's missing for the first sixty seconds. And if everyone's on Steam, you can skip -crossplay entirely and connect by IP, which is marginally more reliable. But the moment one person on the roster is on Game Pass or Xbox, crossplay stops being optional. On our panel it's a toggle, so there's no flag to remember.
World seed and transferring an existing world
Every Valheim world is generated from a seed, a string you can set the first time the world is created. Want a specific map? A big meadows spawn, a Black Forest ringed by ocean, whatever a seed-sharing thread promised you? You set that seed at generation time and never again. It's baked into the .fwl file. You cannot change the seed of an existing world: generating a new one with a different seed just makes a completely separate map.
Bringing a single-player world onto the server is where people get nervous, and it's genuinely simple:
- Find your local save. On Windows it lives under your user AppData in LocalLow, in the IronGate Valheim worlds_local folder. You're after two files that share a name: MyWorld.db and MyWorld.fwl.
- Upload both files, together, into the server's worlds folder. Missing one of the pair corrupts the load, so never move just the .db.
- Set the server's -world parameter to match the file name exactly. It's case-sensitive on Linux servers.
- Start the server and check the logs for the line confirming the world loaded, plus the day count. If your day count matches your single-player save, you're in.
Full FTP and file access turns this into a two-minute job, which is one reason I push people toward a host that gives you the real save directory instead of locking you out of it. You browse to the exact folder, drop both files, done.
Backups: the thing you'll thank yourself for
Valheim writes periodic backups of the world file on its own, but I don't trust the built-in cadence for anything I care about. World saves fire every twenty minutes by default, so a crash at minute nineteen costs you nearly a full session. And corruption does happen, usually after an ungraceful shutdown. A corrupt .db with no backup means starting over.
Do two things. Keep the automatic backups on, then pull a copy off the server on a schedule: a nightly download of the .db and .fwl pair to your own machine covers most groups. Second, before any risky operation (updating the server, changing world modifiers, importing a world) grab a manual copy first. It takes ten seconds, and it's the single habit that separates admins who've never lost a world from the ones who have. Our Valheim plans keep automated backups running server-side, so a bad update or a fat-fingered delete isn't the end of your saga. A local copy is still worth keeping. Belt and suspenders.
Keeping the world alive when nobody's online
Here's the subtle part that catches new admins. By default, the server sleeps the world simulation when no players are connected. It's a deliberate CPU-saving move, but it means your automated tasks (crop growth, boar breeding, kiln smelting) don't advance, and raids don't fire, while the server sits empty.
If you want a genuinely living world, you can stop that idle sleep so the simulation keeps ticking. The trade-off is real CPU use around the clock, and on shared or underpowered hardware that shows up as lag the moment players return. On a properly provisioned box it's a non-issue, and a world where your fermenters actually finish while you sleep feels a lot better to come back to. That's a big part of why people move off a home PC in the first place: a machine at home that's asleep or throttled can't keep the world alive the way a dedicated box in a datacenter can.
Two operational notes to close on. Keep the server binary updated, because Valheim clients refuse to connect to an outdated server after a patch, and a version mismatch strands your whole group until you update. And put the server somewhere with low latency to your players. Ours run in Frankfurt, London, and Gravelines, so most of Europe sees single-digit to low ping, which matters a lot when a two-star troll is winding up a swing.
Get the three basics right (a real password, crossplay if anyone's on Xbox, and both save files moved together) and the rest is maintenance you can mostly automate. If you'd rather not babysit updates, backups, and the idle-sleep setting, that's exactly what a managed game server takes off your plate, and our Valheim hosting ships with the crossplay toggle, file access, and DDoS protection already sorted. Whichever way you go, back up the world before you touch anything. Skol.