Change your server's world seed

The seed only applies when a world is first generated. Typing a new one into your settings does nothing to a world that already exists, so changing the seed means starting a new world. You can keep the old world on disk or delete it.

Checked against Minecraft 26.3 and Paper 26.3, October 2026.

Before you start

• A new world means new terrain. Every build, chest and player inventory in the old world is gone from the server once it is replaced, and only a backup brings it back.
• Mojang changes world generation between versions (1.18, for example, brought a new random number generator for the Overworld), so the same seed can give different land on a different version. Check your version in JAR Manager before you generate.
• Your whitelist, operators and bans are separate files in the top folder, so they stay.

Open the Backups tab and press Create backup first. Create and restore backups has the details.

Keep the old world: use a new folder name

This is the safest route, because nothing is deleted.

1. Press Stop on the Console tab and wait until the server is offline.
2. Open the Config Editor tab and go to the World section.
3. Type the seed you want in World seed.
4. Change World folder to a new name, such as world2. The panel notes that changing it starts a new world while the old folder stays on disk.
5. Press Save changes, then Start.

The old world folder still takes up disk space. Delete it in the File Manager when you are sure you do not want it.

Replace the old world

1. Press Stop on the Console tab and wait until the server is offline.
2. In the Config Editor, type the seed in World seed and press Save changes.
3. Open the File Manager. In the top folder, delete the world folder. The panel asks you to type its name to confirm.
4. If world_nether and world_the_end folders sit beside it, delete those too. From Minecraft 26.1 the Nether and End are stored inside world, so you will not see them there. On Paper 26.1 and newer, a per-world paper-world.yml lives inside each world's dimensions folder, so deleting world removes those per-world overrides too. Copy that file out first if you want to keep it.
5. Press Start on the Console tab. The server generates a fresh world from your seed.

If you leave World seed empty, the server picks a random seed.

Check it worked

Once the server is Running, send seed in the Console (no leading slash). The reply starts with Seed: and shows the number the world was generated from inside square brackets. Copy the number without the brackets. Find your server's world seed explains more.

If the old terrain is still there

• The map did not change. The world folder still existed, so the server loaded it and ignored the seed. Stop the server, delete the folder and start again.
• World folder points at a world that already exists. If a valid world is at that path, the server loads it. If not, it generates a new one there.
• The seed is not the one you typed. If you typed words, Minecraft converts the text to a number, so seed shows a number. Otherwise run seed to see what the world really uses, and check World seed was saved.

To reset the world without choosing a seed, see the guide to resetting your world.