Core Keeper guide

How to move your Core Keeper world to a dedicated server

A Core Keeper world is one file, numbered for its slot. Upload it, point the server at the same slot, and your group carries on underground.

Updated 28 October 2026

Find your world

On Windows, Core Keeper keeps worlds in %USERPROFILE%\AppData\LocalLow\Pugstorm\Core Keeper\Steam\<number>\worlds. Each world is one file named for its slot: 0.world.gzip for slot 0, 1.world.gzip for slot 1, and so on.

On another server, the world is in its worlds folder, named the same way.

Upload it

  1. Set the world slot. In Settings, set World slot to the world's number (0 for 0.world.gzip) and press Save configuration. The server has 30 slots, 0 to 29.
  2. Stop the server. Press Stop in your dashboard.
  3. Upload the world. Open Files & SFTP, choose corekeeper/worlds and press Upload to corekeeper/worlds, then pick the file. Keep the name that matches its slot. Files up to 96 MB upload in the browser; a bigger world goes over SFTP (Generate SFTP credentials).
  4. Wait for the safety scan. Press Refresh until the file shows Passed safety scan.
  5. Start the server. Press Start. The server opens the world in that slot.

Good to know

  • Characters are saved on each player's PC, so everyone brings their own.
  • Admins.json goes in corekeeper/. To become the owner, add your Steam ID in Settings.
  • Steam players join with the Game ID in your dashboard. Players on other PC stores join by IP with the address, port and password.
Core Keeper questions

Good to know.

What if my file has a different number?

Rename it for the slot you want, for example 3.world.gzip for slot 3, and set World slot to match.

Can I keep the server's current world too?

Yes. Use a free slot: each slot keeps its own world, and setting World slot back loads the old one.