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Pre-generate your Minecraft world with Chunky to stop exploration lag

1 min readUpdated Nov 3, 2026Copy link

When players fly or sprint into new land, the server has to generate every chunk on the spot, and TPS drops. Pre-generating does that work once, ahead of time.

Why it helps #

Generating a new chunk (terrain, caves, structures, lighting) is far more work than loading one that already exists. A few players exploring in different directions can push the server into "Can't keep up!" warnings. With the area pre-generated, the server only loads chunks from disk. Combined with a world border, players can't wander past what you generated.

1. Install Chunky #

Chunky is an open-source plugin and mod. Download the build for your server type and Minecraft version from Modrinth or Hangar: the Bukkit/Paper version for Paper and Purpur, or the Fabric/Forge/NeoForge version for modded servers. Upload it to plugins (or mods) in Files and restart (how to add plugins and mods).

2. Start a pre-generation #

In the console (no slash needed):

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

• chunky world picks the world (use world_nether or world_the_end for the others).
• chunky center 0 0 centres on 0, 0; chunky spawn centres on the world spawn.
• chunky radius 3000 covers 3000 blocks in each direction (a 6000 × 6000 square). Start smaller if you're unsure.

Chunky prints progress in the console. You can chunky pause, chunky continue and chunky cancel, and it picks up where it left off after a restart.

3. Set a matching world border #

The vanilla world border uses a diameter, so for a radius of 3000 set 6000:

worldborder center 0 0
worldborder set 6000

Now nobody can reach ungenerated land. If you want more room later, raise the radius, run Chunky again, then widen the border.

Tips for running it on a hosted server #

• Run it when few people are online. Pre-generating uses a lot of CPU, so the server can lag while it runs. Overnight is ideal; you can schedule a restart afterwards with schedules.
• Watch your disk space. Pre-generated worlds are much bigger on disk. Check the world folder size in Files as it runs, and pause if you're getting close to your plan's limit.
• Back up first. Download a copy of your world (backups) before big changes.
• Turn down view distance as well if you still see lag; see fix Minecraft server lag.

FAQ #

Does pre-generating a world reduce lag?

Yes, for lag caused by exploration. Generating new chunks is expensive; loading already-generated chunks is much cheaper. It won't fix lag from farms, redstone or too many entities.

How big a radius should I pre-generate?

Start with what your players actually explore, often 2000 to 5000 blocks, and check the disk space it uses. You can always extend it later.

Can players stay online while Chunky runs?

Yes, but expect some lag while it runs. Running it at a quiet time is best.

Sources: Chunky on Modrinth · Minecraft Wiki: worldborder

Still stuck? Use the live chat on the panel or ask in the ESN Systems Discord. Last updated November 3, 2026.