Valheim 1.0: what changes for your server (world, saves, mods, crossplay)
It's done: since September 9, 2026, Valheim is at version 1.0 (build 25185644, network version 39). The Deep North is here, with its Jotun, 40+ new weapons and a final boss. But behind the launch trailer, Iron Gate's patch notes and official FAQ contain several changes that directly affect anyone running a server. Here's what to know before you relaunch your world this weekend.
Should you start a new world?
The official answer is nuanced. Your old world does receive the new content, but Deep North generation only works properly in areas you have never explored. If you've already sailed to the edges of the map, the new biome will be truncated or missing there. Iron Gate therefore recommends starting over for "the best possible experience".
Our advice for a server: don't decide in a hurry. Back up the current world (a manual backup from the panel takes ten seconds), then create a second world for 1.0. You keep your 200-hour village safe and discover the Deep North the way it was designed. 1.0 also gives you one more reason to explore the world's edges: alternate versions of the earlier biomes now appear there.
A new save system
This is the most important change for reliability. 1.0 splits world data across chunks instead of writing one big file: less data serialized on each save, so faster saves, and above all a format designed to be resilient against mid-write failures. The corrupted-world scenario, where the server stopped at the wrong moment, becomes far less likely.
It doesn't replace a real external backup: our servers keep their automatic daily backups with one-click restore, and the new structure simply makes them faster.
Mods: wait before relaunching a modded server
Nothing has changed in principle: no official mod support, no Steam Workshop, and Iron Gate guarantees no compatibility at launch. In practice, a server running BepInEx with Jotunn, ValheimPlus or building mods will not restart correctly until every mod has been updated for 1.0. The Unity engine was upgraded, which historically breaks a good share of mods.
If your community plays modded, keep the server vanilla for a few days, or wait for the update wave on Thunderstore before re-enabling anything.
Full crossplay: your server becomes the meeting point
1.0 launches simultaneously on PC, Xbox, PS5 and Nintendo Switch 2, with crossplay across every platform. A dedicated server makes complete sense: it's the only place where a PC player, a friend on PS5 and a cousin on Switch 2 share the same persistent world without depending on the host's PC. The limit stays at 10 players per server, as before.
Just remember to enable the crossplay option on your server, otherwise console players won't see it.
Achievements and cheats: careful with admin commands
1.0 introduces achievements, and an anti-cheat system to go with them. Using most devcommands ("spawn", for example) permanently flags the character and the world as cheated, which blocks achievements for everyone. Spawned items are flagged too, and a player who picks one up enters a temporary cheated state.
For a public server admin, that's a real behaviour change: one "spawn" to help a stuck player can cost ten people their achievements. Keep the commands for a test world.
What changes in the world itself
- Snow must be cleared: in the Deep North you can't build until you've shovelled the ground;
- Ice breaks: on frozen seas and ponds, watch your step;
- The Jotun invade Valheim: new events hit your base, not just the new biome;
- The grappling hook changes how vertical your builds can be;
- Kall Fimbulbringer, the final boss, closes the progression;
- Performance-wise: much faster world generation, optimized network traffic for terrain edits, and a new client-side draw distance setting.
Updating your Valheim server
At Game-Servers the update was applied on the evening of September 9: on its next restart your server boots into 1.0. To check, open the panel console and look for the line Valheim version: l-1.0.7 (network version 39). If your players see "Peer has incompatible version", the server is still on the old build: a simple restart from the panel is enough.
No server yet? The free 24h trial with no credit card lets you test 1.0 with your friends tonight, and subscriptions start at €5.99/month with no commitment. All the details are on our Valheim server page, and our Deep North preparation guide still applies for the recommended configuration.
