Valheim 1.0: What Changes for Server Owners

Valheim 1.0 released 9 September 2026 with the Deep North. What it changed for server owners: existing worlds, save format, mods and console players.

August 19, 2026

Valheim left early access on 9 September 2026. 1.0 brought the Deep North, PlayStation 5 and Nintendo Switch 2 on the platform roster, full crossplay between all of them, achievements and a new save format. For anyone playing the game that was a release date. For anyone running a server it was a maintenance window, and there are four decisions to make if you have not made them yet.

This guide is written for the person with the server, not the person with the axe.

Written before launch, updated after it

This page was first written from what Iron Gate had announced before 1.0, and has been updated to what shipped on 9 September 2026 and in the patches since (1.0.16 on 25 September is the latest at the time of writing). Where Iron Gate has been specific we quote them; where they have not, we say so rather than fill the gap. Iron Gate's 1.0 FAQ still carries its 1 July 2026 date and its pre-launch future tense, so the FAQ quotes below are Iron Gate's pre-launch wording.

What Valheim 1.0 Actually Is

Three things at once, and they had different consequences for a server.

It is the end of early access. Valheim entered early access on Steam on 2 February 2021; 1.0 is the full release, five and a half years later. Steam now lists the release date as 9 September 2026.

It is the Deep North. Iron Gate's 1.0 FAQ says the update "focuses on the Deep North biome", with "some new content for the rest of Valheim as well". This is the last biome on the roadmap — when the Ashlands landed in 2024, Iron Gate called it "the penultimate biome of the game". There is no Ocean rework in 1.0; the FAQ rules that out explicitly.

It is more platforms. PlayStation 5 and Nintendo Switch 2 versions went on sale on 9 September 2026. Iron Gate's release-date announcement of 7 June 2026: "The release will hit PC, Linux, Mac, Xbox One and Xbox Series X|S as per usual, and now we're also adding PlayStation 5 and Nintendo Switch 2 to the roster. Of course there will be full crossplay between all the platforms, so that you can play with your friends."

What does not change

Player cap. Iron Gate's FAQ: "Just like it is now, Valheim 1.0 will be a game for 1-10 players." Your saves. "Nothing. Your old saves will still be where you last left them, and you can continue to play with them if you like." Consoles still cannot host. Iron Gate's crossplay FAQ states you cannot set up a dedicated server on an Xbox, and the same holds for the other consoles — they join servers, they do not run them.

Do You Need a New World for the Deep North?

This is the question every server owner asked on the 9th, and Iron Gate had answered it in advance — twice, in different words.

From the 1.0 FAQ, on whether a new world is required:

"As usual, your world will receive new content even if it was created before the update, although biome generation will only work properly on areas that have not yet been explored. However, we always recommend that you start the game over from scratch to get the best possible experience."

And on heading straight for the new biome:

"Can I head straight for the Deep North when I've launched the game? You can, but it's our recommendation that you start over."

So: your world keeps working, and the Deep North generates only where nobody has been. If your players sailed north two winters ago and mapped the ice, that coastline is already committed to disk and the new biome cannot be written over it.

This is not new behaviour and it is not a guess. Iron Gate said the same thing before the Ashlands in March 2024: "As always, new content will only be generated properly in previously unexplored areas of the game. Therefore, if you have already explored a lot of the Ashlands, the update will not generate properly in that world and we recommend that you start a new one."

Keep the world or start fresh

	Keep the existing world	Start a new world
Your base, chests and progress	Kept	Gone (the old world still exists, you just are not in it)
Deep North generation	Only in map areas nobody has explored	Complete
Effort on the day	Restart the server, carry on	New World Name, new join instructions for everyone
Achievements	See the warning below — an old world may already be disqualified	Clean slate
Iron Gate's recommendation	Workable	This one

You do not have to choose — run both

A Valheim server loads whichever world matches its World Name setting, so keeping the old one costs you nothing but disk. Leave the existing world's folder in place, set World Name to something new, and restart: Valheim generates the new world and the old one sits untouched next to it. Switch back by putting the old name in the field again. Valheim Server Settings and Launch Arguments covers the field, and How to Upload Your Existing World to Your Valheim Server covers moving worlds around by hand.

There is one thing Iron Gate has not told us about old worlds

The Ashlands update also rewrote terrain around the biome, and Iron Gate warned that player structures built on altered terrain would collapse. Nothing in the 1.0 FAQ says whether the Deep North does anything similar to the far north of an existing map. It might not — but if you have a base up there, that is an argument for a snapshot you can actually roll back to, not an argument for optimism.

Back Up Before You Update — There Was No Test Branch

Iron Gate's FAQ closed the door on staging:

"Will there be a Public Test Branch for 1.0 before release? No. We want everyone to get to experience 1.0 at the same time!"

There was no way to boot a 1.0 server against a copy of your world before the 9th, no way to check your mod stack, and no way to see what the update would do to your map. The only safety you get is the one you take yourself, and the same routine applies to every patch since.

Before an old world first loads on 1.0, or before any patch:

Run save in game as admin, then stop the server cleanly from the panel. Valheim's automatic save runs on the -saveinterval cycle — 30 minutes by default — so an unplanned restart can otherwise cost half an hour of building. Use Stop, not a force kill: Iron Gate's own warning about the desktop server is that closing the window instead of shutting down properly means "the Server may keep running in the background, we don't really know!"
Take a manual snapshot, not just the scheduled one. See How to create a backup. Valheim's own -backups copies live on the same disk in the same directory as the world they protect, which is exactly the wrong place for them if something eats that directory.
Grab the world files as well. A 1.0 world is a folder in worlds_local/; a pre-1.0 world that has not been loaded on 1.0 yet is still a matching .db and .fwl pair. Either way, copy the whole thing — pull it down over SFTP if you want a copy that is not on the server at all.
Tell your players to back up their characters. Characters live on each player's own machine, not on your server, so this is the one part of the backup you cannot do for them.

The save format changed at 1.0 — this is what it looks like now

The rewritten save system Iron Gate trialled on the public test branch shipped with 1.0. A world is no longer a .db/.fwl pair; it is a folder named after the world inside worlds_local/. Inspected on a live 1.0 server, a freshly generated world holds _main.N.fwl2 (metadata), _main.N.db2 (world data), _main.N.chunks (the chunk index), one or more NN_NN__N_N.chunk files, and _main.N.ok, a marker written last so an interrupted save is recoverable. The number increments each save.

Pre-1.0 worlds still load — Valheim converts them on first open, taking a backup first. Iron Gate has since said that worlds converted before Patch 1.0.12 lost the levels and variants of items on item stands and armour stands; worlds converted from 1.0.12 onwards convert correctly, and restoring that first-load backup is one of their two suggested fixes. Move and back up the whole folder, never files out of it. Valheim save location and the 1.0 world folder format has the full breakdown, and uploading an existing world the migration steps.

Mods Will Break

Assume every BepInEx plugin on your server stopped working on the 9th until its author shipped a 1.0 build. This is not pessimism; it was Iron Gate's own position:

"Just like always, it takes some time for mods to be updated to be compatible with the base game. Since we don't have any official mod support, we cannot guarantee that any mods will be functional when 1.0 releases."

And because there was no public test branch, no mod author got an early build to compile against. Updates could only start appearing after release day.

Worse than a mod that does not work is a mod that stops the game booting. Iron Gate's guidance before the Ashlands was unusually specific about this, and there is no reason to think 1.0 was gentler:

"If you're using mods, it's therefore recommended that you disable them before you download the [update], otherwise the game will most likely not launch properly. To disable mods you will also need to remove BepInEx or any other mod loader, as they might try to load regardless."

The practical version for a hosted server: switch Server Type to vanilla, get a clean 1.0 boot, confirm players can connect, and only then start putting plugins back one at a time as their authors ship rebuilds. How to install mods for your Valheim server covers the server types and how to tell whether a mod is still maintained.

Note that this cuts both ways for your players. A client-side mod that fails to load takes their game down, not your server — so if exactly one person cannot get in after an update, ask what they have in their BepInEx folder before you touch anything.

Console Players Can Join Now — One Setting Decides Whether They Get In

PlayStation 5 and Nintendo Switch 2 players have no way onto your server unless it is running Valheim's crossplay backend. Iron Gate's dedicated server guide, verbatim:

"-crossplay — Runs the Server on the Crossplay backend (PlayFab), which lets users from any platform join. If you do not include this argument, the Steam backend is used, which means only Steam users can see and join the Server."

On a hosted server that is the Enable Crossplay field in the Startup tab. A self-hosted server left on Valheim's own default is invisible to every Xbox, PlayStation and Switch 2 player — not slow, not hard to find, invisible. On a GameServerKings Valheim server that field ships set to Yes, so console players can see it from first boot; confirm it has not been switched off rather than assuming it was never on.

Switching backends changes three things you should know before your players do:

A join code appears in the pause menu, and it changes every time the server restarts — including your scheduled nightly restart. Share the IP and port for anything permanent.
Local and loopback addresses stop working. Iron Gate: you connect to a crossplay server by public IP and port, by join code, or through the server list, but not from a local address.
Console players browse, they do not type. Set Public to 1 and give the server a distinctive, correctly spelled name, because the name is the only handle they have on it.

Two platform requirements are worth knowing so you are not blamed for them. The PlayStation Store listing states "PS Plus required for online play", and Nintendo's Switch 2 listing points at a Nintendo Switch Online membership. Neither is anything you can configure — but "my PS5 friend can see the server and cannot join" has an answer that is not your server.

Admin rights change shape too. Iron Gate documents the format as one case-sensitive Platform User ID per line in adminlist.txt, written [Platform]_[User ID] and obtainable "from the Server log or from within the game using the F2 panel". A PlayStation or Switch 2 player has no SteamID64 to fall back on, so read the ID off the F2 panel.

Is Valheim Crossplay? has the full platform matrix and the cross-save answer, and How to Play Valheim With Friends covers how people actually join.

Achievements: One Sentence You Need, Then Go Read the Detail

1.0 added achievements, and Iron Gate built a cheat detector that flags the world save, not just the offending character — permanently, and retroactively for characters that used cheats before 1.0.

On a server that has been running for a year and has ever had an item spawned into it, that decision may already be made. Since Hotfix 1.0.12 on 11 September 2026, Steam players can opt back in with the devcommand yesiuseddevcommandsbutiwantmyachievementsanyway, and Patch 1.0.14 fixed characters being wrongly marked as temporary cheaters. Valheim Console Commands quotes Iron Gate's wording in full and works through what triggers the flag, which commands are exceptions, and how spawned items spread a temporary version of the state to players who never opened a console. Read it before you promise anyone achievements on the old world.

Sizing, Performance and What 1.0 Does Not Fix

Download size. Iron Gate: "Valheim 1.0 will be about 4.3GiB in size to download on most platforms. Xbox One will be slightly smaller at around 3.0GiB, while the Mac AppStore and Microsoft Store versions will be about 6.5GiB in size." Those are figures for the game, on players' machines. The dedicated server is a separate Steam application and Iron Gate has not published a 1.0 size for it.

Player count. Still 1–10. A larger allocation buys headroom for a big base and heavy world generation, not more slots. If you are sizing a server for a 1.0 world rather than tuning one you already have, the Valheim hosting plans list what each tier allocates.

Performance. Iron Gate lists "decreasing the microstutters that occur when loading new zones in and out of memory, faster saving, and many other minor optimisations" — then heads off the obvious hope: "large builds in particular would not be highly impacted by these changes." Faster saving is the one that shows up server-side, because every save writes the world and stutters for everyone on it. If your problem today is a thousand-piece longhouse, 1.0 is not the fix Iron Gate is selling.

Your 1.0 Checklist

If your server has not been touched since before 9 September, work through this before your players log in.

Decide old world or new world and tell your players which, so nobody arrives expecting a fresh start they are not getting.
Turn crossplay on if a single console player is joining, and have someone actually connect to prove it.
Take a manual snapshot and pull a copy of the world off the server — the .db/.fwl pair if it has not loaded on 1.0 yet, the whole world folder if it has.
Ask players to back up their characters — that part is on them.
Note your current server build so you can tell whether it has actually updated. The version is in the bottom-right of the client's main menu.
Run vanilla until each mod you rely on has a 1.0 build, and warn anyone who depends on a mod.
Let the server update, then restart it. Clients update themselves and will not be able to join a server still on the old build — Valheim version mismatch and update problems covers what that looks like and how to fix it.
Re-share the join code after the first restart, because it will have changed.

What Iron Gate Has Not Said

Being straight about the gaps is more useful than filling them:

Whether the Deep North alters terrain in existing worlds the way the Ashlands did. The 1.0 FAQ does not mention it either way.
Whether -preset Hammer on a dedicated server locks achievements. The FAQ names "hammer-mode" as a world modifier that blocks certain achievements and "counts as a temporary cheat", and the dedicated server guide lists Hammer as a preset value, but no Iron Gate document connects the two names. Valheim Console Commands explains why we are not going to assume they are the same thing.
An updated FAQ. The 1.0 FAQ is still dated 1 July 2026 and still written in the future tense. What Iron Gate has said since launch is in the patch notes, 1.0.10 to 1.0.16.

FAQ

Will my existing Valheim world work after the 1.0 update?

Yes. Iron Gate: "Nothing. Your old saves will still be where you last left them, and you can continue to play with them if you like." The catch is not whether it loads, it is that the Deep North only generates in areas nobody has explored.

Do I need a new world to see the Deep North?

Not strictly. New content reaches an existing world, but "biome generation will only work properly on areas that have not yet been explored", and Iron Gate recommends starting over for the best experience. If your map's far north is already explored, a new world is the only way to get the biome intact.

Can I keep my old world and run a new one?

Yes. Change World Name in the Startup tab and restart — Valheim generates a new world under that name and leaves the old files alone. Change it back to switch worlds.

Will my mods work at 1.0?

Iron Gate could not guarantee any of them would, and there was no public test branch for authors to build against, so updates could only arrive after release. Run vanilla until each mod you use has a 1.0 build. See installing mods.

Do I need to do anything for PS5 and Switch 2 players?

One thing: enable Crossplay on the server and restart. Without it the server runs on the Steam backend and only Steam players can see or join. Console players cannot host a server, only join one.

Will 1.0 make my server run better?

Marginally. Iron Gate lists faster saving and fewer zone-loading microstutters, but says explicitly that large builds "would not be highly impacted". The player cap is unchanged at 1–10.

Should I update the server to 1.0?

Yes — but back up first, and expect a short window where clients have updated and the server has not. Restart the server after each update lands so it picks up the new build.