Valheim Server Best Practices

Valheim

5 min readIntermediateLast updated Oct 30, 2026

A Valheim server is simple to run once it's set up well. The things that go wrong are a world growing beyond its memory, weak access control, and worlds lost because backups lived in the wrong place.

Checklist

[ ] Memory sized for your world, not just your player count. Memory
[ ] A strong password: 5+ characters, not part of the server or world name. Public Server 0 for friends-only servers.
[ ] Admins in adminlist.txt, only people you trust. permittedlist.txt if only invited players should join. Admins and access
[ ] Valheim's own backups on, and panel backups every 6–12 hours. Backups
[ ] A locked backup before every game update and before big boss fights.
[ ] Auto Update on; for modded servers, check your mods first. Mods
[ ] A daily restart at a quiet time.
[ ] Two ports (your port and the next one up) on Network, or crossplay on.

Memory

Valheim's memory use grows with how much of the world has been explored and built, not only with players. An old world with big bases needs more than a new one with the same group.

Server	Memory
New world, up to 10 players (Valheim's maximum)	4 GB
Well-explored world with large bases	6 GB
Modded, or big mod lists	8–12 GB

The CPU matters as much as memory: Valheim leans on one fast core. Large bases with many lit fires, lots of build pieces and many tamed animals in one area cause lag that more memory won't fix. Spread them out, or thin out decoration.

Admins and access

These files sit next to your worlds in .config/unity3d/IronGate/Valheim/, with one SteamID64 (a 17-digit number starting 7656…) per line. Players can find theirs by pressing F2 in game. Edit with the server stopped, or restart after saving.

File	Effect
`adminlist.txt`	Admins: can kick, ban and use admin commands in the F5 console.
`bannedlist.txt`	Banned players.
`permittedlist.txt`	Whitelist: as soon as it has one entry, everyone not listed is blocked. Being listed doesn't make someone an admin.

Valheim has no remote console (RCON), so admin commands are run in game.

Backups

Valheim keeps its own backups of the world. Set them on Startup if your server shows them; the defaults are:

Setting	Default	Meaning
Save interval	1800 s	How often the world is saved (30 minutes).
Backups	4	How many automatic backups to keep.
Short backup interval	7200 s	Time between the first backups (2 hours).
Long backup interval	43200 s	Time between later backups (12 hours).

Those backups are stored in the same folder as the world, so a mistake or a disk problem loses both. Keep panel backups every 6–12 hours too, and download one now and then. Backup schedules

To restore:

Stop the server. A running server saves over anything you restore.
Restore the whole worlds_local folder from a panel backup, or copy back one of Valheim's backups.
Keep each world's .db and .fwl together from the same backup. Mixing files from different times can corrupt the world.

Restarts

Valheim saves the world when it shuts down cleanly, and long-running worlds slowly use more memory. A daily restart at a quiet time keeps it tidy: a schedule with a Restart power action (times are UTC). The panel stops the server properly, so the world saves first.

Ports and crossplay

Valheim uses two UDP ports: the one on your Network page and the next one up (2456 and 2457, for example). Without the second, players can't connect by address. Ask us if it's missing.
Crossplay lets Xbox and Game Pass players join with a join code, and connects through Valheim's relay, so it works even when ports are a problem. Turning crossplay on or off changes the join code.
Crossplay servers must be vanilla: mods need crossplay off.
Don't rely on the in-game community list: join by address or join code.

Updating

Make a backup and lock it.
Restart (Auto Update downloads the patch).
Modded servers: see when an update breaks mods.

Common problems

Problem	Fix
Server won't start, bad password in the console	The password is under 5 characters, or it's part of the server or world name.
Incompatible version	The server or the player isn't up to date. Restart the server; players update in Steam or Xbox.
Friends can't connect by address	The second port is missing. Ask for it, or turn on crossplay and use the join code.
World reset / empty world	World Name doesn't match the uploaded files' name.
Everyone except one player is blocked	`permittedlist.txt` has entries, which turns it into a whitelist. Add everyone, or empty it.
Lag near one base	Too many build pieces, fires or tamed animals in one place. Spread them out.
Modded players kicked on join	Mod or version mismatch. Everyone must use the same modpack version.