The Ultimate Guide to Pre-Generating Your World with Chunky

If you have ever tried to start a Minecraft server, you have likely encountered the “exploration lag” phenomenon. As players sprint across the landscape or fly with Elytra, the server’s CPU works overtime to generate new terrain, place structures, and calculate lighting for every single chunk. This intensive process is the number one cause of TPS drops on even the best Minecraft servers.

To run a high-performance, low lag minecraft server, you need to stop generating the world in real-time and start pre-generating it. This guide will teach you how to use Chunky, the industry-standard tool for pre-generation, to ensure your players enjoy a smooth, professional experience from day one.

What is Pre-Generation (And Why Does It Matter?)

Minecraft generates its infinite world in 16×16 sections called “chunks.” By default, these chunks are created only when a player moves close to an unexplored area. This “on-demand” generation is incredibly resource-heavy.

Pre-generation is the process of forcing the server to create and save these chunks to the disk before players ever set foot in them. When you pre-generate with Chunky, you are effectively trading storage space for CPU performance. Instead of the CPU “calculating” the world, it simply “reads” it from your minecraft server hosting storage.

The Benefits of Using Chunky

Eliminate Stutter: No more block-lag or “rubber-banding” while exploring.
Stable TPS: Keep your server at a constant 20 TPS, even with multiple explorers.
Custom World Gen Support: Essential if you use complex terrain generators like Terraforged or Iris.
World Border Integration: Perfectly define your playable area to keep file sizes manageable.

Step-by-Step Guide: How to Pre-Generate Your World

Before you begin, ensure you have a backup of your world. While Chunky is extremely stable, it is best practice to always have a recovery point when performing major world operations.

1. Installation

Chunky is available as both a plugin (for Paper, Spigot, and Purpur) and a mod (for Fabric and Forge).

For Plugins: Download the .jar from SpigotMC and place it in your /plugins folder.
For Mods: Download the version for your loader from Modrinth and place it in the /mods folder.
Restart: Restart your server to generate the configuration files.

2. Selecting the World

By default, Chunky will target the world you are currently standing in. If you are running the commands from the console, you must specify the world name.

/chunky world world

(Replace “world” with “world_nether” or “world_the_end” for other dimensions.)

3. Setting the Center and Radius

Next, you need to tell Chunky where to start and how far to go. Usually, you will want the center to be your spawn point ($0, 0$).

Set Center: /chunky center 0 0
Set Radius: /chunky radius 10000 (This will generate a 20,000 x 20,000 block area).

4. Choosing the Shape

You can generate in various shapes depending on your needs. A square is the default and most efficient for storage, while a circle provides a more natural boundary.

Command: /chunky shape square

5. Starting the Task

Once configured, initiate the process:

Command: /chunky start

Understanding World Size and Storage Requirements

One common mistake when you start a Minecraft server is over-generating. Chunks take up physical space on your drive. If your minecraft server hosting plan has limited NVMe/SSD space, you must choose your radius carefully.

Radius (Blocks)	Total Area (Blocks)	Approx. Disk Space (Vanilla)	Estimated Time (Fast CPU)
1,000	2,000 x 2,000	~200 MB	10 Minutes
5,000	10,000 x 10,000	~4 GB	2 – 4 Hours
10,000	20,000 x 20,000	~17 GB	12 – 24 Hours
20,000	40,000 x 40,000	~65+ GB	2 – 4 Days

Pro Tip: Always leave at least 20% of your disk space free for logs, backups, and player data. If you fill your disk to 100%, your world may become corrupted.

Advanced Chunky Commands and Tips

To truly master your public minecraft server performance, you should familiarize yourself with Chunky’s management commands.

Check Progress: /chunky progress — Shows percentage, chunks processed, and estimated time remaining (ETA).
Pause/Resume: /chunky pause and /chunky continue. Useful if you need to free up CPU for an event.
Silent Mode: /chunky silent — Prevents progress messages from spamming your console or chat.
Trimming: /chunky trim — This is a powerful command that deletes all chunks outside of your selected radius. It is perfect for cleaning up a world where players explored too far.

Integrating with ChunkyBorder

While pre-generating creates the chunks, it doesn’t stop players from wandering past the generated edge and causing new lag. For this, we recommend the ChunkyBorder addon.

Unlike the vanilla world border, ChunkyBorder allows for custom shapes (like circles or stars) and provides a smoother “bounce-back” mechanic.

Set your Chunky selection.
Run /chunky border add.
This automatically syncs your world border to your pre-generated area.

Common Mistakes to Avoid

Generating While Players are Online: Pre-generation is a CPU-intensive task. Running it during peak hours will cause massive lag. Use /chunky pause when your player count rises.
Using Slow Storage: If your minecraft server hosting uses traditional HDDs (Hard Disk Drives), pre-generation will be incredibly slow. Always opt for NVMe SSDs for world files.
Ignoring the Nether and End: Many admins forget to pre-generate dimensions. The Nether is especially laggy due to its dense terrain and lava flow calculations.
Forgetting the Memory: Pre-generation can spike RAM usage as chunks are held in the cache before being written to the disk. Ensure you have at least 4GB of RAM allocated. Check out [CPU vs RAM: What Actually Stops Minecraft Lag in 2026?] for more details on hardware balance.

FAQ: Pre-Generating Your World

Does pre-generating affect my world seed?

No. Pre-generating simply “activates” the seed’s terrain early. The world will look exactly as it would have if a player explored it manually.

Can I pre-generate a modded world?

Yes. Chunky works perfectly with minecraft server plugins and mods. In fact, it is more important for modded servers because modded world generation is often 3-5x more intensive than vanilla.

How do I know if my world is already pre-generated?

If you can fly at high speeds with Elytra and chunks appear instantly without the “void” effect, your world is likely pre-generated. You can also check your world folder size; a vanilla world with a 10k radius will usually be over 15GB.

Is Chunky better than WorldBorder’s “Fill” command?

Yes. Chunky is more modern, better optimized for newer Minecraft versions (1.18+), and handles the increased world height much more efficiently than the older WorldBorder plugin.

Conclusion

Pre-generating your world with Chunky is the single most effective step you can take to move your project into the ranks of the best Minecraft servers. By removing the burden of terrain generation from your CPU, you ensure that your server remains snappy, responsive, and professional.

Before you launch your next public minecraft server, take the time to set a radius, run /chunky start, and let your hardware do the heavy lifting while you’re offline. Your players—and your server’s TPS—will thank you.

Ready to optimize your server further?