Pre-generate a Minecraft world with Chunky
Chunky pre-generates Minecraft chunks so players walk into terrain that already exists, which cuts lag spikes from live worldgen. Radius is in blocks. On berrybyte Paper servers, install it from Overview → Plugins → Manage plugins, then run chunky radius, chunky start.
Chunky writes Minecraft chunks to disk before anyone walks there. Players then load finished terrain instead of forcing the server to generate it live, which is the usual source of exploration lag.
On berrybyte, install the plugin on Paper and similar loaders from Overview → Plugins → Manage plugins. Radius is measured in blocks.
Create a backup first. A large radius grows the
world folder quickly, and chunky trim deletes chunks you cannot get back
without that backup.
Install Chunky
Open Manage plugins
On a running or stopped Paper (or similar) server, open Overview → Plugins → Manage plugins and search Chunky.
Install and start
Install the plugin. If the server is already up, restart it so the jar
loads. You can also drop a jar into Files → plugins/.
Confirm it loaded
In Console, run chunky. You should see the current world, shape,
center, and radius. Default is usually a square overworld at 0, 0
with radius 500.
Download the matching loader build
Get Chunky from Modrinth or
CurseForge for Forge, NeoForge, or Fabric. Do not put the Paper jar
in mods/.
Upload it
Stop the server, upload the jar to Files → mods/, then start
again.
Run commands from Console
Modded servers still use the same chunky command family from
Console or an operator account.
Pre-generate a region
Run these from Console (no leading slash) or in-game as an operator (with a slash).
Pick the world
chunky world world for the overworld. Use world_nether and
world_the_end for the other dimensions, or whatever those folders are
named in Files.
Set the center
chunky center 0 0 unless your spawn is elsewhere. chunky center
with no numbers uses your current position if you run it in-game.
Set the radius in blocks
chunky radius 5000 is 5,000 blocks from center, a 10,000 × 10,000
block square. For chunks, use a c suffix: chunky radius 625c.
Start generation
chunky start. Console prints percent complete, ETA, and chunks per
second. chunky status repeats that line. chunky pause /
chunky resume hold the job. chunky stop cancels it.
chunky shape circle generates fewer corner chunks than the default
square, which saves time and disk for the same radius.
Size at a glance
| Radius (blocks) | Area (square) | Rough disk | Typical time on NVMe |
|---|---|---|---|
| 1,000 | 2,000 × 2,000 | under 1 GB | a few minutes |
| 5,000 | 10,000 × 10,000 | 2 to 4 GB | under two hours |
| 10,000 | 20,000 × 20,000 | 8 to 15 GB | several hours |
Start at 5,000 if you are unsure. Raise it later with another chunky radius
and chunky start. Chunky skips chunks that already exist.
Pause or finish map plugins such as Dynmap while this runs. They fight Chunky for disk and can slow both jobs.
Commands
| Command | What it does |
|---|---|
chunky world <name> | Select which dimension to generate |
chunky shape square|circle | Outline of the region |
chunky center <x> <z> | Center in block coordinates |
chunky radius <n> | Radius in blocks (625c for chunks, 10k for 10,000) |
chunky start | Begin or continue generation |
chunky pause / resume | Hold or continue the job |
chunky stop | Cancel the job |
chunky status | Progress, ETA, chunks per second |
chunky trim | Delete chunks outside the selection. Irreversible |
Official command list: Chunky wiki.
After it finishes
Set a vanilla world border to the same radius if you want players to stay on
pre-generated land (/worldborder center 0 0 then /worldborder set 10000
for a 5,000-block radius). Pre-generate the Nether and End the same way if
people will travel there.
If join lag remains after a finished job, the cause is usually RAM, view distance, or garbage collection, not missing chunks. See Aikar's flags and the Minecraft hub.
Frequently asked questions
Is Chunky radius in blocks or chunks?
Blocks, unless you add a c suffix. chunky radius 5000 is 5000 blocks from the center (a 10,000 by 10,000 block square). chunky radius 625c is 625 chunks.
Can players stay online while Chunky runs?
Yes. Generation uses CPU and disk, so expect some lag. Overnight or a quiet window is smoother. Use chunky pause and chunky resume if you need the server snappy for a session.
Does Chunky work on Forge or Fabric modpacks?
The Paper, Spigot, and Folia plugin is what berrybyte installs from Manage plugins. Forge, NeoForge, and Fabric builds exist on Modrinth and CurseForge and go in mods/, not plugins/.
Will Chunky fill my disk?
A 5,000-block radius is often a few gigabytes. A 10,000-block radius can be 8 to 15 GB depending on the world. Start smaller, check Files, then raise the radius.
Do I need a world border?
Chunky does not set a vanilla world border. Set one in server.properties or with the vanilla /worldborder command if you want players to stay inside the pre-generated area.