Pre-generate Chunks with Chunky

Why Pre-generating Chunks is Useful for Performance

Chunky and other pre-generation methods can help with server performance by doing all the hard work up front. This means that while players explore the server, they will not have to generate any chunks as they travel, as long as they are within the area that was pre-generated. Chunk generation can cause severe performance drops if players attempt to travel very quickly and generate tons of land, especially in heavily modded servers. With Chunky, you can set a specific area to be pre-generated, and even set a world border to keep players in that area to maximize performance. Or just generate an area you think will be sufficient and let players explore further if needed.

Here is the link for all versions of Chunky. You can download Chunky for Forge, Fabric, Neoforge, Bukkit, Folia, Paper, Spigot, and Sponge. If you don't know which version of Chunky to download, it is likely Forge or Fabric, depending on your modpack, or Spigot if you don't have a modpack.

How to Install Chunky on a Server

I will provide a step by step guide below on the basics of using Chunky. There are many advanced functions and customization options that will not be covered here. If you want more information, be sure to check out the Chunky wiki here.

First, install Chunky. Click this link to see how to add a mod to an existing modpack on a server.
Instructions for the plugin version can be found here.

Chunky only needs to be on the server, and it does not need to be installed on your client.

How to Pre-generate Chunks

Now that everything is set up, connect to your server. Make sure you have OP privileges on the server. Here is how to do that, if you haven't already.

For this example, I have a Forge 1.20.4 server set up with Chunky installed. Commands may differ by Chunky version. I will be generating a square with a radius of 5000 blocks, or meters. Here are the steps I will take to do this:

  1. Run the command /chunky center which will set the center of the area to my location.
  2. /chunky radius 5000 which sets the radius of the area to 5000 blocks.
  3. /chunky shape square which sets the shape of the area to be square.
  4. /chunky world minecraft:overworld which tells Chunky to perform the following operation in the overworld. You can use any dimension you want for this, in newer versions of Chunky it will let you tab autocomplete through the different available worlds.
  5. /chunky start which starts the operation. You will see a progress bar at the top of your screen with a percentage complete and a rough time estimate of time remaining. The server will lag during this process. Once the process is complete, the bar will go away.

If you want to pause the operation you can run /chunky pause or /chunky resume. If the server restarts, the operation will pause. You can run the resume command to resume it. You can also change the chunky configuration file to make all operations resume upon a server restart automatically. You can cancel the operation entirely by running /chunky cancel.

If you have generated an area, but you want to generate more later, you can start another generation operation with a larger radius. You can safely generate an area that overlaps with an area already pre-generated, and existing chunks will be skipped.

There are many more options and settings and commands, but those are the basics needed to start pre-generating. Check out the Chunky wiki here for more information on how to use some of the more advanced features.


Warning: pre-generation area grows in size exponentially. Start small if you don't know how much you want to pre-generate. 5000 is a good starting radius. Depending on the modpack, large operations can take hours or even days to complete, running 24/7.