How to Pregenerate a World on a Minecraft Forge Server

Pregenerating your world can make your Forge server run smoother by creating all the terrain in advance instead of generating everything on the fly. This helps reduce lag, improves player experience, and gives you more control over how the world loads. In this guide, we will walk through what pregeneration is, why it matters, and how to set it up using a world-generation mod on your Forge server. By the end, your server will have a fully built terrain ready to explore. 

Note: Be sure that your Minecraft server is fully stopped before making any configuration changes or installing mods.

Install a Pregeneration Mod

To pregenerate a world, you will need a mod that handles the terrain building process. Chunky, Chunk Pregenerator, and World Pre Generator are some of the most common options, depending on which Minecraft version your Forge server runs. All of them follow a similar process and work well for server-side pregeneration.

1. Navigate to your Minecraft server dashboard.

2. Open the Server Files.

3. Confirm that your server has a mods folder. If it does not, create one.

4. Upload the pregeneration mod JAR file into the mods folder.

5. Start your server once to allow the mod to create any needed config files.

6. Stop the server again after the configs have been generated.

Once the mod is installed, you are ready to begin pregenerating your world.

Start the Pregeneration Process

Each pregeneration mod uses a slightly different set of commands, but the overall process is the same. You will tell the mod how far to generate and then start the task. 

1. Start your server.

2. Join your server or open the server console.

3. Run the mod’s pregeneration setup command. Examples include:

   • Chunky: /chunky radius 5000 followed by /chunky start

   • Chunk Pregenerator: /pregen start gen radius 5000

4. The mod will now start generating the terrain. This can take anywhere from a few minutes to several hours depending on the size of your world and your server hardware.

You can continue to monitor progress while the tool is running but avoid restarting the server until the task is complete. 

Monitor Your Progress

Pregeneration puts an extra strain on your server while it works, which is normal. Expect higher than usual CPU usage and slower response times during this process. Some mods include a feature to automatically pause pregeneration when players are logged in, and then resume when they log out, to prevent any gameplay issues.

Here are a few things to keep in mind:

• Most mods provide progress updates directly in the console or in-game chat

• Some versions show chunk counts, percentages, or time estimates.

• Do not stop or restart the server while pregeneration is active.

• Larger worlds take significantly longer to complete, so patience is key.

Once the tool reaches 100%, you can safely stop the server.

Choose the Right Generation Size

The size of your pregenerated world matters. Too small and your players will reach the edge almost immediately. Too large and your server may take hours to generate terrain that nobody will explore.

Here are a few general guidelines for radius sizes:

• Small groups or private servers: 2000 to 4000 radius

• Medium exploration servers: 5000 to 8000 radius

• Large communities or modpacks with heavy exploration: 10,000 or higher

Keep in mind that radius is measured from the center of the world. A radius of 5000 generates a world that is 10,000 blocks wide.

If you decide later that you need more space, you can always rerun pregeneration to extend your world borders.

Finishing Up

Once pregeneration finishes, stop your server and decide whether you want to keep the mod installed. Some server owners remove it after the world is created, while others keep it for future updates. Either approach works, as long as you do not interrupt the process while it is running.

After restarting your server, everything will load faster since all the terrain is already generated. Your players can explore without sudden lag spikes, and your server will have a much easier time keeping up with the activity.

With the world fully pregenerated, your Forge server is set up for smooth gameplay from the moment players join. This simple performance step helps reduce lag, supports exploration-heavy modpacks, and creates a stable world that feels polished and ready to play. Now that everything is generated in advance, you can focus on building, exploring, and enjoying the world without interruptions from terrain loading.

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