# Pregenerate your world with Chunky

> Generate the chunks before players do: the one change that removes most lag from modded and busy servers.

Source: https://fadehost.com/docs/pregenerate-the-world/

New chunks are the most expensive thing a Minecraft server does, and they are generated exactly when a player walks into them. Pregenerating the area your players will use turns that into a one-time job while nobody is on.

## Install Chunky

**Resources**, **Plugins** (Paper) or **Mods** (Fabric, Forge, NeoForge), search Chunky, **Install**, restart. Many modpacks ship it already; `chunky` in the console tells you.

## Run it

In the **Console**:

```
chunky radius 3000
chunky start
```

That generates a 6,000 by 6,000 block square around spawn. `chunky pause` and `chunky continue` stop and resume; `chunky progress` shows where it is. For the nether and end:

```
chunky world world_nether
chunky radius 1000
chunky start
```

(On vanilla, Fabric, Forge and NeoForge the nether is `DIM-1` inside the world.)

## How big and how long

| Radius | Blocks across | Time on a fast core (vanilla) |
| --- | --- | --- |
| 2000 | 4,000 | about 30 minutes |
| 3000 | 6,000 | about an hour |
| 5000 | 10,000 | a few hours |

Modpacks with heavy worldgen take several times longer. Run it before launch night, keep the server up while it runs, and pair it with a world border of the same radius so nobody walks past the edge.

## Disk

Pregenerated chunks take space: a 6,000 block square is a few GB on vanilla, more with modded worldgen. 30 GB is included; extra storage is a dollar per 10 GB. See [Allocate RAM](/docs/allocate-ram/) for the rest of the sizing.