Why run a dedicated server at all
When one player hosts from the game menu, the world only exists while that player is online, and everyone else's connection depends on their home upload speed. A dedicated server keeps the world running around the clock, so anyone in the group can log in, build and sail without waiting for the host.
It also separates the world from any one person's PC. If the host stops playing, the world does not go with them.
How much RAM and CPU Valheim needs
A vanilla server for a handful of players is comfortable in 2 to 4 GB. Memory use climbs with how much of the world has been explored and built on, and with mods, rather than with the player count alone.
Valheim runs its world simulation mostly on one core, so a fast core matters more than many cores. If a busy base stutters when several players are in it, that is CPU and the size of the base, and more RAM will not fix it.
Our Valheim plan is 4 GB for €10.99 a month with VAT included, which leaves headroom for a modded world.
- 2 to 4 GB RAM for a typical group
- One fast CPU core
- Ports 2456 and 2457 over UDP by default
- A password of at least 5 characters, which the server requires
How BepInEx mods work on a server
BepInEx is the mod loader almost every Valheim mod is built on. You install it on the server, then drop mods into its plugins folder. Most mods are published on Thunderstore, which also lists what each one depends on.
The part that trips people up is where a mod has to be installed. Some mods only change the server, such as backup or admin tools. Many change the game itself, and those must be installed on the server and on every player's PC, at the same version. If one player is missing a required mod, or has a different version, they are usually refused at login.
The safest way to run a modded group is to agree one mod list, keep it in a shared Thunderstore profile, and update everyone together.
Crossplay and console players
Crossplay is a launch option. Starting the server with the crossplay flag lets players on other platforms join through the game's backend service, usually by a join code rather than an IP address.
Two things to know before you turn it on. Console players cannot install mods, so a server that requires client mods is PC only in practice. And crossplay routes connections differently from a direct IP connection, so test it with your group before you rely on it.
World files and backups
A Valheim world is two files with the same name: one ending in .db that holds everything built and changed, and one ending in .fwl that holds the world's seed and settings. They belong together. Restoring one without the other gives you a broken or blank world.
Back both up before every game update and before adding or removing mods. To move a world from a player's PC to a server, upload both files to the server's worlds folder over SFTP and set the world name in the launch options to match. That is all a migration is.
What it costs to rent a Valheim server
Renting is a flat monthly price, set by memory rather than by player slots. At Puranode the Valheim plan is €10.99 a month for 4 GB, VAT included, with no setup fee and no minimum term.
Running it at home costs nothing extra on paper, but the PC has to stay on all day, your group shares your home upload, and your home address is where everyone connects. For a group that plays at different times, a rented server is usually the simpler answer.