Pre-generate your world to stop exploration lag

How big should the map be?

Bigger is not better. Every chunk takes storage, and a 5,000 block radius already covers more than most communities ever walk. Check the free storage in the panel first; a large map can take several gigabytes.

From the World tab

1. Open the World tab and find Pre-generate the world.
2. Choose how far from spawn to generate.
3. Start it. The panel installs Chunky if it is not there yet and begins generating.
4. Leave the server running. You can follow the progress in the Console.

Run it when few people are online, such as at night. Players can stay on, but the server works hard while it generates.

With Chunky commands

Chunky is the tool behind the button, and you can drive it yourself from the console for more control, for example to do the Nether as well.

chunky world world
chunky center 0 0
chunky radius 3000
chunky start

• chunky pause and chunky continue stop and resume. Progress survives a restart.
• chunky world world_nether and a smaller radius, since Nether distances count eight times, does the Nether.
• chunky spawn sets the centre to the world spawn instead of 0 0.

On Paper the dimensions are named world, world_nether and world_the_end. On Fabric and Forge, use minecraft:overworld and minecraft:the_nether instead.

Add a world border

Pre-generating does not stop players from walking past the edge into new land. A world border does. Set it to the same size as the area you generated. The border takes a width, which is twice the radius:

worldborder center 0 0
worldborder set 6000

That border matches a Chunky radius of 3000. Players who reach it simply cannot go further, and the server never has to generate new terrain again.

Good to know

• Generation speed depends on the world type and mods. A heavy modpack generates far slower than the normal game.
• A Minecraft update that changes world generation, such as new biomes, only applies to chunks that did not exist yet. Pre-generated land keeps the old terrain.
• Generating a new world after a reset? Run it again; the old progress belonged to the old world.