Every Valheim world you have ever explored, from the gentle Meadows to the burning Ashlands, was built from a single short string of text called a world seed. Understanding seeds is the difference between rolling the dice on a random map and deliberately spinning up a world you already know is perfect for your group. This guide covers exactly how seeds work, how to set a specific seed on a dedicated server (there is a trick here, because there is no simple launch flag), how the underlying world files work, and how to read the seed back out of an existing world.
What a Valheim world seed actually is
A world seed is the value that initializes Valheim’s pseudo-random world generator. From that single starting point, the game deterministically decides everything about the map: terrain shape, biome placement, where rivers and oceans fall, resource distribution, and the location of bosses, dungeons, and points of interest. The crucial consequence is this: the same seed produces the same world layout for a given game version. Two players on opposite sides of the planet who enter the identical seed will get identical maps, which is why seeds get shared in communities and seed-finder websites.
That “for a given game version” qualifier matters. Valheim is still in Early Access in mid-2026, with the Ashlands biome and the Call to Arms update as the latest live content, and version 1.0 (which brings the Deep North biome) scheduled for September 9, 2026. When the world-generation code changes between major versions, the same seed can produce a different layout. If you and a friend want matching worlds, you both need to be on the same build.
What a seed string looks like
A Valheim seed is a short alphanumeric text string, commonly between 1 and 10 characters. Examples you will see shared online look like HHcLC5acQt or something equally terse. They are case-sensitive, so treat them as exact strings rather than something you can casually retype from memory.
There is one widespread misconception worth correcting up front: the seed is not derived from the world name. When you create a new world, Valheim opens a dialog with a world-name field and a separate seed field. The seed field is pre-filled with a randomly generated seed, and you simply replace that random value with your own if you want a specific world. The name and the seed are completely independent. You can have two worlds named differently that share a seed, or two worlds with the same name and different seeds.
Generating a seed at world creation
The simplest way to get a seed is to let the game make one for you. In singleplayer or a listen-server (where you host directly from your game client), creating a new world walks you through these steps:
- Start a new game and choose to create a new world.
- In the creation dialog, type a world name in the name field.
- Look at the seed field. It already holds a random seed the game generated for you.
- To use that random world, leave the field alone and create. To use a known seed, clear the field and type or paste your chosen seed string in its place.
- Create the world. The seed is now locked in.
This is the heart of seed practice: a seed is chosen once, at creation, and can never be changed afterward. There is no command, file edit, or menu that lets you re-roll the seed of an existing world while keeping your progress. If you decide you want a different layout, you generate a brand-new world with the new seed and start fresh. That permanence is exactly why it pays to pick deliberately.
The world files: .db and .fwl
Before we get to dedicated servers, you need to understand how Valheim stores a world on disk, because the seed lives inside a specific file and the dedicated-server seed workflow depends entirely on moving these files around. Every world is stored as two files that share the world’s name:
| File | Contains | Why it matters |
|---|---|---|
WorldName.fwl | World metadata: name, seed, and configuration | This is where the seed is stored. Read it to find a seed. |
WorldName.db | World progress: terrain edits, buildings, chests, dropped items, creatures | This is your actual save. Back it up religiously. |
Both files must travel together. A .fwl without its matching .db is just a configuration header with no world built behind it, and a .db without its .fwl has no seed or name to anchor it. Whenever you back up, copy, or migrate a world, always move the pair.
Where the world files live (the savedir)
The folder that holds your worlds is the “save directory,” and its location depends on how you play:
- Local / self-hosted client worlds on Windows:
%USERPROFILE%/AppData/LocalLow/IronGate/Valheim/worlds_local/ - Local / self-hosted client worlds on Linux:
~/.config/unity3d/IronGate/Valheim/worlds_local/ - Dedicated server: a
worlds_local(orworlds) folder under the server’s save directory.
On a dedicated server you can override where saves are stored with the -savedir launch parameter. This is genuinely useful: pointing the save directory at fast storage (an SSD) helps performance, and it keeps your worlds in a predictable, easy-to-back-up location separate from the game binaries. On a managed host, the world files sit beside the server’s save directory wherever -savedir points, which is also where you will find the adminlist.txt file.
Setting a specific seed on a dedicated server
Here is the single most important thing to know, and it surprises almost everyone: there is no seed launch flag for the Valheim dedicated server. You cannot write something like -seed MyCoolSeed in your start script and have the server build that world. The dedicated server’s start command only lets you name a world via -world and set the save directory via -savedir. If you point -world at a name that does not exist yet, the server auto-generates a fresh world with a random seed you do not control.
So how do you get a specific seed onto a dedicated server? You generate the world locally first, then upload it. This is the verified, reliable method:
- In your Valheim game client, create a new world and enter your desired seed in the seed field (as described above).
- Load into that world and play for one to two minutes. This forces the game to generate and write both the
.fwland the.dbfile. A freshly created world that you never load may not have a complete.db. - Exit and locate both files in your local
worlds_localfolder. - Upload both
WorldName.fwlandWorldName.dbinto the server’sworlds_localfolder (or wherever-savedirpoints). - Set the server’s
-worldparameter (the “World name” setting on managed panels) to that file’s name, without the extension. - Restart the server. It will load your uploaded world, seed and all.
On a self-hosted setup, the world and save directory are defined in your start script (start_headless_server.bat on Windows or the equivalent Linux start script). The relevant parameters look like this:
valheim_server -nographics -batchmode -name "My Server" ^
-port 2456 ^
-world "MyUploadedWorld" ^
-savedir "C:\valheim-saves" ^
-password "changeme" ^
-crossplayNotice the -world "MyUploadedWorld" matches the filename of the .fwl/.db pair you uploaded (minus the extension), and -savedir points at the folder containing the worlds_local directory those files sit in. Valheim’s default game port is 2456 (the server also uses the next couple of ports above it for queries), so make sure that range is open if you are self-hosting. If you would rather skip the local-generation dance entirely and have a panel where you upload world files and set the world name in a couple of clicks, a managed Valheim dedicated server plan handles the start script and port forwarding for you.
The alternative approach, simply setting -world to a brand-new name and letting the server auto-generate, is fine if you do not care which world you get. But because you cannot dictate that auto-generated seed, it is useless for matching a specific shared seed. For any deliberate seed, use the upload method.
How to view an existing world’s seed
You will frequently need to read a seed back, whether to share your world, to recreate it on a new server, or just out of curiosity. There are three reliable ways.
In-game world-select list
The easiest method: in the game client, the seed is displayed right next to each world’s name in the world-select list. If the world is one you can load in your own client, you never have to touch a file. This does not directly help with a server-only world, though, which is where the file method comes in.
Reading the seed from the .fwl file
The seed is stored as plain text inside the .fwl file. Open WorldName.fwl in a text editor such as Notepad++ (a robust editor handles the file’s binary header more gracefully than basic Notepad). You will see the world name on the first line and the seed string on the second line. That second line is your seed. This is the only way to retrieve the seed of a world that lives only on a dedicated server, where you have no in-game world-select entry to read from.
Online seed extractor tools
If you would rather not crack open a file, online “seed extractor” tools parse the .fwl for you. You upload the file, and the tool reads out the seed. These are handy when paired with a seed-map viewer that then renders the whole map from that seed so you can scout biome and boss locations before you commit. They work the same way the manual method does, just with a friendlier interface.
Good seed practices
Because a seed is permanent once chosen, a little planning goes a long way. Here is how experienced server admins approach it.
- Scout before you commit. Use a seed-map viewer to check a candidate seed: how close are the early bosses, is there a generous Black Forest near spawn, are the Mistlands and Ashlands reachable without an absurd ocean crossing? Since the seed locks the whole map, scouting saves a doomed restart later.
- Record the seed somewhere safe. Drop it in your group’s Discord, a pinned note, or your server documentation. If your save ever corrupts and you have backups of the seed but not the
.db, you can at least regenerate the same terrain. - Back up both files before any risky change. Before opting into a beta branch, installing mods, or upgrading the game version, copy the
.dband.fwlpair out to a safe folder. The.dbholds all your built progress and is irreplaceable. - Match game versions when sharing. If you want a friend to experience the identical map, confirm you are both on the same Valheim build. A seed that produced a particular layout on an older version may generate differently after a world-gen update.
- Keep the name and seed documented together. Since the two are independent, note both. Knowing the seed alone is enough to recreate the terrain, but matching the original world name keeps your start scripts and file references consistent.
For the full set of dedicated-server parameters, admin-list setup, and panel-specific steps, the official Valheim documentation walks through the start script and save-directory configuration in detail.
Related server topics worth knowing
Seeds are only one piece of running a healthy Valheim server. A few neighbouring topics come up constantly once you are managing a world. First, console commands: be aware that on a vanilla dedicated server, admins can only use a limited set of commands (kick, ban, save, ping, world modifiers). The familiar cheats like spawn, fly, and god are world-owner-only and do not work on a dedicated server unless you install a mod for them. Our guide to Valheim console commands and the creative-mode prefab list covers exactly which commands work where.
If your shared world starts feeling laggy as your base grows, that is usually not a seed problem at all. Valheim’s dedicated server is largely single-threaded and has a hard-coded per-client send/receive limit of roughly 64 KB/s, which is the most common cause of rubber-banding in multiplayer. Our breakdown of how to fix lag and desync on a Valheim dedicated server explains the fixes. And if you are still deciding how to host the world in the first place, the comparison of dedicated versus slot-based Valheim hosting is worth reading, because for Valheim, CPU clock speed and RAM matter far more than raw player-slot counts.
Frequently asked questions
Can I change the seed of an existing Valheim world?
No. The seed is locked at the moment the world is created and stored in the .fwl file. There is no command or supported file edit that re-rolls the seed while keeping your progress. If you want a different map, you must generate a brand-new world with the new seed and start over. This is why scouting a seed in a map viewer before you commit is so valuable.
How do I find the seed of my dedicated server world?
Because a server world does not appear in your in-game world-select list, you read it from the file. Download the world’s .fwl file from the server’s worlds_local folder (or wherever -savedir points) and open it in a text editor like Notepad++. The world name is on the first line and the seed string is on the second line. Alternatively, upload the .fwl to an online seed-extractor tool, which reads it out for you.
Is the seed the same as the world name?
No, and this is a common mistake. When you create a world, there is a name field and a separate seed field. The seed field is pre-filled with a random value that you can replace. The world name and the seed are completely independent of each other, so changing the name has no effect on the map, and the same seed can be used under any name you like.
Will two players on the same seed get the same map?
Yes, provided they are on the same game version. The seed deterministically generates terrain, biomes, resources, and boss and dungeon placement, so an identical seed produces an identical layout. The caveat is the game version: world-generation code can change between major updates (Valheim is still in Early Access in 2026, heading to version 1.0 on September 9, 2026), so a seed shared across mismatched versions may not match perfectly.
What are the .db and .fwl files, and which one has the seed?
Every world is two files sharing the world’s name. The .fwl file holds the world metadata, including the name, the seed, and configuration, so the seed lives in the .fwl. The .db file holds your actual world progress: terrain edits, buildings, chests, dropped items, and creatures. Always back up and move both files together, since they are useless apart.
Why is there no -seed launch option for the dedicated server?
Valheim’s dedicated server simply was not built with a seed parameter. The start script only exposes -world (the world name) and -savedir (the save location). If the named world does not exist, the server auto-generates one with a random seed you cannot control. To put a specific seed on a server, create the world locally with that seed, play it for a minute or two so both files generate, then upload the .fwl and .db pair into the server’s worlds_local folder and set -world to that filename.
Where are Valheim world files stored?
For local and self-hosted client worlds on Windows, they are in %USERPROFILE%/AppData/LocalLow/IronGate/Valheim/worlds_local/, and on Linux in ~/.config/unity3d/IronGate/Valheim/worlds_local/. A dedicated server keeps them in a worlds_local (or worlds) folder under its save directory, which you can relocate with the -savedir launch parameter. Pointing -savedir at fast SSD storage is a small but real performance win.
That covers the full lifecycle of a Valheim seed: how it is generated, where it lives, how to plant a specific one on a dedicated server, and how to read it back out. Pick your seed deliberately, back up your .db and .fwl together, and you will never lose a world you love. For more on tuning the server itself, see our guides on adding mods to a dedicated Valheim server and managing your world once it is live.
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