Valheim World Seeds: Find, Set and Use a Seed on a Server
A Valheim dedicated server cannot be given a seed with a launch parameter. When the World name does not match an existing world, the server creates a new world with a random seed. To play a seed you picked, create the world on your PC with that seed, then upload it to the server. A seed cannot be changed after a world is created.
This guide covers what a seed decides, how to read the seed of a world already on your server, how to host a specific seed on ChicagoServers, and why a fresh seed is worth considering since Valheim 1.0 and the Deep North update. It was checked in November 2026 against the community Valheim wiki, host documentation for 1.0 and our own server files. Valheim changes often, so confirm against Iron Gate's patch notes after an update.
- There is no
-seedlaunch parameter. A server world gets a random seed when the server creates it, and the seed is stored in the world's settings file. - To host a seed you choose: create the world on your PC with that seed, enter it once, upload the whole world, then set World name on the Startup tab to match. See the world transfer guide for the upload details.
- To read the seed of a server world: stop the server, download the world's settings file (
.fwl2inside the world folder on 1.0,.fwlbefore) from the Files tab and open it in a text editor. The name and seed are readable text. - A seed is fixed for the life of a world. A different seed means a new world, so back up first and keep the old one to switch back to.
- Seeds are case-sensitive, and the same seed can generate a different map on a different game version. Deep North only generates in ground nobody has explored, so older, well-travelled worlds may suit a fresh seed.
On this page
- What a Valheim seed is and what it decides
- How a dedicated server picks a seed
- Find the seed of a world already on your server
- Host a Valheim seed you choose
- Switch to a new seed without losing the old world
- Seeds after Valheim 1.0 and the Deep North
- Troubleshooting seed and world problems
- Frequently asked questions
What a Valheim seed is and what it decides
A seed is a piece of text that the world generator turns into a map. The same seed on the same game version produces the same world: the same terrain, biome layout and locations. Changing a single character produces a different world. The seed box in the world creation screen is filled with a random string of ten letters and numbers, and you can replace it with your own text. Seeds are case-sensitive, so Midgard and midgard are different seeds.
The world is a circle about 20 km across (a 10 km radius). Meadows is at the centre, where players spawn. Ashlands sits far to the south and, with Valheim 1.0, the Deep North sits at the far northern edge. Those are the broad strokes; where the swamps, mountains, plains and bosses fall is the part the seed decides.
What the seed does not decide is the world name, anything players build, or the world modifiers (difficulty settings). Those belong to the saved world. Characters are stored on each player's PC, so they work in any world on any server.
How a dedicated server picks a seed
The server has the -world launch parameter and no seed parameter. On ChicagoServers that parameter is the World name field on the Startup tab. The community wiki puts it this way: the server creates a random seed and gives the world the name you specify in -world.
| What you set | What the server does |
|---|---|
World name matches a world in the server's worlds_local folder | Loads that world with the seed it already has. |
| World name matches nothing, or you made a typo | Quietly creates a brand-new world with that name and a random seed. It does not warn you. |
| You upload a world made on your PC, then set World name to its name | Loads it, with the seed you chose when you created it. |
Find the seed of a world already on your server
The seed is saved in the world's settings file, so you can read it without playing. Do this with the server stopped so you are not reading a file mid-save.
- Stop the server
Open your server in the panel at panel.chicagoservers.co and click Stop at the top of the page.
- Open the world folder
Go to the Files tab and open
saves/worlds_local. On Valheim 1.0 each world is a folder named after the world. Worlds from before 1.0 are a.dband.fwlpair. - Download the settings file
On 1.0, open the world's folder and download its
.fwl2file. If several have different numbers, take the highest, which is the newest save. For an older world, download the.fwlfile, which is the smaller of the two. Do not download the large.dbor.db2file. - Read it in a text editor
Open the file in a plain text editor such as Notepad++ (not a word processor). Most of the file is not readable, but the world name and the seed appear as plain text. Copy the seed exactly, including capital letters.
A second route: copy the world folder into worlds_local on your PC (see the world transfer guide for the Windows path) and open Valheim. Host documentation reports that the world list in the game shows each world's seed next to its name. If yours does not, use the text editor method above.
Host a Valheim seed you choose
Because the server cannot take a seed, you generate the world on your PC and move it over. Pick a world name that is different from the one your server uses now, so you cannot overwrite it by accident.
- Create the world on your PC
In Valheim, choose your character, then New world. Enter a world name and your seed. Names and seeds with the same spelling but different capitals are different.
- Enter it once, then quit to the menu
Spawn into the world and exit to the main menu so the game writes the world files. Community documentation recommends starting the world at least once before copying it.
- Back up the server's current world
On the Backups tab, choose World and settings and click Back up now. Star it so it is not replaced. Then click Stop at the top of the page.
- Upload the world
On the Files tab, open
saves/worlds_localand upload the whole world folder from your PC (Valheim 1.0), or both the.dband.fwlfiles for an older world. If the server already has a world with that exact name, remove or rename it first. The world transfer guide has the Windows path and the SFTP route for large worlds. - Point the server at it
On the Startup tab, set World name to the world's name, click Save startup, then Restart. Watch the Console tab for Game server connected.
- Check it is the right map
Join and look at the surroundings. If you land in a different world than the one you made, the name did not match and the server created a new one. Fix the name rather than playing on it.
Switch to a new seed without losing the old world
A world keeps its seed for good, so changing seed means switching worlds. This is safe because worlds sit side by side in worlds_local, and the World name decides which one loads.
- New random seed: back up, then change World name on the Startup tab to a name that does not exist yet and restart. The server creates a fresh world with a random seed and leaves the old one where it is.
- Chosen seed: use the PC method above.
- Go back: set World name to the old name and restart. Its buildings, bosses and progress are in its own files.
- Players: their characters carry over to any world, but a new world means new boss progress and a new map. Tell your community before you switch.
Seeds after Valheim 1.0 and the Deep North
Valheim 1.0 and the Deep North update released on 9 September 2026. It adds a new frozen biome and alternate versions of earlier biomes around the outer reaches of the world. Iron Gate's FAQ, as quoted by host documentation, says biome generation only works properly on areas that have not yet been explored.
- Old world, lightly explored: it can keep running. New content appears where nobody has walked.
- Old world, sailed and explored widely: you may see little or none of the Deep North or the new outer-edge biomes. A fresh seed is the way to get the whole experience, and Iron Gate recommends starting over for the best experience.
- Old seeds: do not assume a seed you used in 2021 still makes the map you remember. World generation can change between versions, so the same seed can look different on 1.0. Test a seed in singleplayer before you commit the server to it.
- Seed viewer tools: community map previewers are built for particular game versions. Only trust one that says it supports your version, and treat it as a rough preview, since it cannot show everything the game generates.
Troubleshooting seed and world problems
| What you see | Likely cause |
|---|---|
| The server made a different world than you expected | World name does not match your uploaded world exactly. Check capitals, spaces and the folder name. |
| The map does not match a seed guide or map previewer | The seed was typed with different capitals or a stray space, or the tool was built for another Valheim version. |
| The server will not start after choosing a seed | The Join password is under five characters, or it appears inside the world name or seed. |
| Players cannot see the Deep North | That part of the world was explored before 1.0. Start a world on a fresh seed. |
| You cannot find the settings file | The world is a folder on 1.0, so open it and look for the .fwl2 file. Check you are in worlds_local and not a backup folder. |
| Players cannot join after the switch | Client and server are on different builds. Click Update now on the Steam update bar, then update the clients. |
Want a Valheim server where world switches, backups and file access are a few clicks? The Valheim server hosting page lists what is included, such as free server backups, SFTP file access and a one-click BepInEx installer.
Frequently asked questions
Can I set a seed with a launch parameter on a Valheim dedicated server?
No. Valheim's dedicated server has no seed parameter. The server names a new world after the -world value and gives it a random seed. To use a seed you choose, create the world on your PC with that seed and upload it to the server.
How do I find the seed of my Valheim server world?
Stop the server, open the Files tab, download the world's settings file (a .fwl2 file inside the world folder on Valheim 1.0, or a .fwl file on older worlds) and open it in a plain text editor. The world name and seed show as readable text. Seeds are case-sensitive.
Can I change the seed of an existing Valheim world?
No. A world's seed is fixed when it is created and the terrain is generated from it. To use a different seed, create a new world and switch the server's World name to it. The old world stays in the worlds_local folder if you want to go back.
Is the Valheim world name the same as the seed?
No. They are separate. The world name decides which world files load, and the seed is stored inside the world's settings file. A server-created world gets a random seed, whatever its name.
Does the same seed always make the same Valheim world?
On the same game version, yes. Between versions, world generation can change, so an older seed may not recreate the map you remember. Check a seed in singleplayer on your current version before using it on a server.
How big is the Valheim world?
The playable world is a circle about 20 km across, a 10 km radius. Meadows is at the centre, Ashlands is far to the south and the Deep North, added in Valheim 1.0, is at the far northern edge.
Do I need a new seed for the Valheim 1.0 Deep North update?
Only if you want all of it. Deep North and the new outer-edge biomes generate only in ground nobody has explored, so a world that was explored widely before 1.0 may show little of it. A fresh seed gives the full experience.