Core Keeper Dedicated Server: How to Host One (Steam Tool, Self-Hosted or Rented)

Yes, Core Keeper has dedicated servers, and the Core Keeper dedicated server tool is free on Steam. Run it on a PC that stays on, or on a rented machine, and your world is up whether or not you're playing. If you only need a world for a Friday night, you don't need it at all: the in-game Game ID route does the job.

Here's how the three routes compare, how to set up the Steam tool, and who can and can't join. Details are as of October 2026.

Do you even need a Core Keeper server?

In-game hosting: load your world and character, press Escape, pick "Copy game ID" (top left) and send it. Your friend picks "Join Game", pastes it into "Enter Game ID" and joins. The world only exists while you're playing it. That's the whole catch, and for a small group that plays together on a schedule, it's fine. My Core Keeper crossplay guide walks through the same flow.

A dedicated server earns its keep when people want to drop in without you.

How to host a Core Keeper dedicated server

The tool is listed on Steam as Core Keeper Dedicated Server, app ID 1963720. Don't mix it up with the game itself, which is a different ID. It runs on Windows and Linux, and the download is free and anonymous, so the server machine doesn't need to own the game.

1. In Steam, install it (it shows in your Library under the Tools filter), or use SteamCMD on a machine with no Steam client.
2. The SteamCMD version on Windows: steamcmd +force_install_dir c:\corekeeperdedicatedserver\ +login anonymous +app_update 1963720 +quit
3. Run Launch.bat. A PowerShell window opens and prints your Game ID. It also lands in GameID.txt next to the exe.
4. Leave that window open. Press Q in it to stop the server properly. Closing the window can leave the process running in the background.

Share the Game ID and players join like they would any other game, through Join Game. That mode goes through Steam's relay, so no router settings are involved.

Launch arguments worth knowing

Every option is documented in ARGUMENTS.txt in the install folder, which has been bundled since update 1.1.0. These are the ones most people touch:

Stick to 8 players or fewer. The server will accept a higher number, but ARGUMENTS.txt warns about instability, and 8 is what the game officially supports. Add arguments to your launch script, and read ARGUMENTS.txt for the rest. Options get added with updates, so trust the file that shipped with your install over any old guide.

Joining: Game ID vs IP, port and password

There are two ways in, and which one you get depends on whether you set a port.

• Game ID (default): no port set. Players paste the ID into Join Game. No port forwarding.
• Direct connect: start the server with -port and forward that UDP port on your router. Players join with your IP, the port and the password.

If you leave out -password, the server makes up a random one for direct connections, so set your own if you want to hand it out. Behind CGNAT, direct connect won't work from outside, and that's a good reason to rent. My Terraria server hosting guide covers port forwarding and CGNAT in more detail, and it carries over to this game.

Who can join (and who can't)

• Consoles can't join a PC dedicated server. The publisher says Core Keeper crossplay only covers PC stores to each other, plus console families within themselves. There are no plans for console and PC. If you came here from a PS5 search, that's the answer.
• 8 players on PC, PS5, PS4, Xbox One and Xbox Series X|S. Switch caps at 4.
• Steam players are the safe bet. Epic, GOG and Microsoft Store players can be hit or miss on a dedicated server. Have them turn crossplay on in their Gameplay settings and test a join before you pay for anything.

Moving your existing world to a server

This is the one people get stuck on. Worlds are files named N.world.gzip, where N is the slot. On Windows, the game keeps yours in %APPDATA%\..\LocalLow\Pugstorm\Core Keeper\Steam\<SteamID>\worlds\. The server keeps its own in %APPDATA%\..\LocalLow\Pugstorm\Core Keeper\DedicatedServer\worlds\.

1. Stop the server and keep a copy of your original world file somewhere safe.
2. Copy the world into the server's worlds folder. If the folder isn't there yet, it appears after the server first saves, around 30 seconds after someone logs in. You can also create it by hand.
3. Match the slot. The server loads slot 0 by default, so either rename your copy to 0.world.gzip or start the server with -world N. If the slot doesn't match, you'll get a brand-new world instead.

Backups

Stop the server and copy the worlds folder into a dated folder somewhere else. That's it. Do it before updates and before you try anything new. For your own client saves, the main menu has a shortcut: Ctrl+Alt+B writes CoreKeeperSaves.zip to your desktop.

And don't post your Game ID in public. Anyone who has it can join.

Renting a Core Keeper server

Renting gets you a world that's always up, no router settings and no CGNAT problems, and a control panel instead of a script. Several game hosts list Core Keeper. Plans and prices change often, so compare a few current listings. Rented servers often use direct connect (IP, port, password) rather than a Game ID, so check which one your host uses. If your group is mixed across PC stores, test a join before you commit to a plan.

If you already run Docker, community-made Core Keeper server images exist too. They're unofficial, so expect to do your own troubleshooting.

I'd self-host if you've got a spare PC and don't mind a script. If you don't, rent.

Still deciding what to play with your group? I've got lists of games like Terraria and games like Enshrouded. The same hosting questions come up in my Valheim dedicated server and 7 Days to Die dedicated server guides.