Worlds: switch, upload and reset

The Worlds tab

The Worlds tab lists every world on your server, its size, and which one is active right now.

The active world is the one your server opens on start, and its name lives in server.properties under level-name. Switching worlds writes the new name there, and the world only opens after you restart the server.

Switch world

Pick the world in the table and press Activate. Restart a running server to open the new world. The old world stays exactly where it is, and you can go back to it the same way whenever you want.

Upload a world from your computer

A world is a zip with a folder inside it that holds level.dat. From the Worlds tab:

1. Press Upload world and pick the zip
2. Keep the page open until the progress bar finishes. We upload the file, unpack it, and add the world for you
3. Activate the new world, then restart the server if it's running

The world takes its name from the folder inside the zip, and you never have to rename anything before you upload. If a world already uses that name, we add a number, so a second world arrives as world-2 and a third as world-3, and its Nether and End folders follow the same name. A folder named without Latin letters or digits becomes world. A zip holding several worlds imports all of them in one go. Whichever name a world lands on, we tell you right after the upload.

Moving from Aternos

Your world downloads from the Aternos Worlds page at aternos.org/worlds: select the world, press Download, and a zip of that world lands on your computer. Upload that zip here exactly as it came down, without unzipping or renaming anything.

1. Download the world from the Aternos Worlds page
2. Press Upload world here and pick the zip you downloaded
3. Activate the imported world, then restart the server

Your server already has a world named world, so an Aternos world lands beside it as world-2. Nothing is overwritten, and you pick which one is active.

Create or copy a world

Use Create world to choose a name and optional seed. The new world becomes active and generates at the next start, and your previous world stays available. Use Copy world on a row to copy that world and all its dimensions under a new name without activating it.

Turn on hardcore for a world

In hardcore, each player has one life, and a player who dies becomes a spectator. The difficulty becomes Hard and stays locked while hardcore is on. On Java, hardcore is saved inside the world itself, so the Hardcore field in Settings only applies to worlds created after you turn it on. For a world you already have, set it here.

1. Stop your server.
2. Open Worlds, choose Set hardcore on the world, then turn the switch on or off.
3. Start your server.

A ✓ in the Hardcore column marks each world that has it on. You can turn it off again from the same place at any time, and the server goes back to the difficulty in Settings the next time it starts.

Download a world to your computer

Select Prepare download on the world's row, then Download after it finishes. Stop the server first if you want a clean copy, because a running world writes its files at any moment. The ZIP includes the overworld and all existing Nether and End folders, including the sibling folders used by older Paper and Purpur versions.

The export stays in .serverk-exports until you replace it or delete it from Files. Prepare it again when you want a fresh copy. Exports are excluded from backups. Upload accepts Java worlds only. Native Bedrock worlds belong on a native Bedrock server.

Reset the Nether or the End

Reset the Nether and Reset the End delete that dimension completely, and it generates again the next time someone enters it. Handy when everything has been looted, or when you want a fresh dragon.

Delete a world

Delete deletes the world with its Nether and End for good. You can't delete the active world, so activate another one first.

A delete or a dimension reset can't be undone, and we don't take a backup before it. Take a backup first, and restore it to bring the world back:

Worlds and backups

Every world on your server goes into the backup. Leave five old worlds parked and your backups grow, take longer, and use up your disk. Delete what you don't need, or download it first and then delete it here.