How to Use Chunky in Minecraft

If your Minecraft server stutters every time players push into unexplored territory, ungenerated chunks are almost certainly the cause. Chunky solves this by pre-generating chunks before anyone sets foot in them — forcing the server to do that heavy CPU work upfront so it doesn’t happen mid-session when players are online.

You set a radius and center point, Chunky generates chunks in the background while the server runs, and the process can be paused and resumed at any time. This guide covers installation, configuration, running generation, and monitoring progress.

Pre-generating a large world is CPU-intensive — Physgun’s Minecraft server hosting runs on high-performance hardware so chunk generation completes faster and doesn’t tank performance while players are online.

Step 1: Install Chunky

The correct version of Chunky depends on your server software:

Download the build that matches your exact Minecraft version — mismatched versions will cause crashes or fail to load.

Place the file in the correct folder, then restart your server. Confirm Chunky loaded by checking the console output on startup or running /plugins (Paper/Spigot) or /mods (Forge/Fabric).

Step 2: Prepare Before Generating

Before starting any pre-generation run:

• Back up your world. If something goes wrong during generation, you’ll want a clean restore point.
• Estimate disk space. A 100-chunk radius generates roughly 10 GB of world data. Scale accordingly for larger radii.
• Schedule during off-peak hours. Generation is CPU-intensive. Running it while players are online will cause noticeable lag — ideally run it overnight or during a maintenance window.
• Notify players if the server will be under load or temporarily restricted during generation.

Step 3: Configure Your Generation Area

Set the center point and radius before starting. All Chunky commands can be run from the server console or in-game as an operator.

Set the center point (defaults to world spawn if omitted):

/chunky center <x> <z>

Set the radius in chunks:

/chunky radius 500

Set the shape — circle covers a round area, square covers a rectangular one:

/chunky shape circle

or

/chunky shape square

Tip: If you want to enforce the pre-generated boundary and prevent players from exploring beyond it, install the ChunkyBorder addon alongside Chunky.

Step 4: Start Pre-Generation

Once your radius and shape are configured, start the generation:

/chunky start

To target a specific dimension:

/chunky start world_nether
/chunky start world_the_end

Chunky automatically skips chunks that already exist, so running it multiple times or overlapping runs is safe — it won’t regenerate existing terrain.

Step 5: Monitor and Manage the Task

Check progress:

/chunky status

This shows percentage complete, chunks processed, and the current task.

Pause generation (useful if the server needs resources for players):

/chunky pause

Resume where it left off:

/chunky resume

Cancel the current task entirely:

/chunky cancel

Chunky saves progress automatically, so pausing and resuming across server restarts works without losing your place.

Command Reference

Troubleshooting

Chunky doesn’t appear in /plugins
Confirm the .jar is in the plugins/ folder (not mods/) and that the Chunky version matches your server version exactly. Check console output on startup for load errors.

Server lags heavily during generation
Chunky is CPU-intensive by design. Reduce the load by running generation when fewer players are online, or use the /chunky pause command during peak hours and resume overnight.

Generation stops unexpectedly
Check your server logs for out-of-memory errors. Increase your server’s allocated RAM if needed, and ensure you have sufficient disk space for the radius you’ve set.

Chunks already exist but lag still occurs
Pre-generation only removes the cost of initial chunk generation. If lag persists, the issue may be entity count, redstone, or other per-tick operations rather than chunk loading.