Generate a new world or set a seed

How do I reset the world or use a specific seed?

Set the seed in Quick Settings, then delete (or rename) the world folders and start the server; a new world is generated from the seed.

Before you start: A backup of the current world if you might want it back.

Step by step

1. Take a backup, or download the world folder from Files.
2. Stop the server so the old world is not in use (deleting a world while it runs corrupts the new one).
3. In Quick Settings, set the level seed (numbers or text) and, if you like, the level type. Save.
4. In Files, delete or rename the world folders: world, world_nether and world_the_end (use your level-name if it is different).
5. Start the server. It creates a fresh world with the new seed.
6. To keep the old world as well, rename it instead (for example world_old); you can switch back by changing level-name.

Check it worked: Joining shows the new terrain; /seed prints the seed you set.

Why it happens: The seed only matters when a world is created; an existing world keeps its terrain.

More guides on Control panel and server setup:

• Start your server for the first time
• Power buttons, and a server stuck starting
• Change the server software or Minecraft version
• Change the MOTD, max players, difficulty, gamemode or PvP
• Edit server.properties and other configs
• Startup settings, Java flags and memory