What Is the World Pre Generator Mod?
Minecraft worlds are vast, and exploring them often triggers chunk generation on the fly, which can cause lag spikes, rubberbanding, and even server crashes when multiple players move quickly across the landscape. The World Pre Generator mod tackles this problem head-on by allowing you to generate all the chunks in a specified area ahead of time. Originally designed for servers, this mod runs commands that systematically create terrain, structures, and biomes so that when players eventually arrive, everything is already loaded and ready to go.
The mod works with a wide range of Minecraft versions, though support is limited to releases where the mod itself is available. Version 5.X.X is the current branch, and older versions are documented in the mod’s wiki. While the mod is only required on the server side, it can also be used on a singleplayer client if you want to pre-generate a world for later server use or simply to test performance. The pre-generation tasks run sequentially, resume automatically after server restarts, and skip chunks that are already generated unless you explicitly force a full regeneration.
Why Pre-generate Your World?
Chunk generation in Minecraft is resource-intensive. When a server must create dozens of new chunks simultaneously because several players are flying in different directions, the tick rate can plummet. Pre-generation eliminates that strain. By running the generation process during off-hours or before players join, you ensure a smooth experience with minimal lag. This is especially useful for large survival servers, modded adventures with heavy worldgen, or any scenario where you plan to have a defined world border. Instead of waiting for players to stumble into new terrain, you define the radius, execute the command, and let the mod handle the rest.
Getting Started with World Pre Generator
Installation and Requirements
Since the mod is primarily a server tool, you place the .jar file into the server’s mods folder just like any other Forge or Fabric mod. No client installation is needed, but you can drop it into your client’s mods folder if you want to pre-generate a singleplayer world. If you are setting up a server for friends and need a quick, managed solution, you can rent a pre-configured server from various hosting providers. For those who prefer a streamlined local setup, this mod can be easily installed via the foxygame.net launcher — a convenient, flexible, and modern Minecraft launcher where you can download mods right from the menu. It handles modpack assembly and version management, making the process almost effortless.
Server Configuration
After the first run, the mod creates a configuration file named world_pre_generator-server.toml inside the serverconfig folder of your world directory. For servers, the world folder name is set in server.properties; for singleplayer, it’s the save name found in the saves folder. The config lets you tweak several important options:
- send_feedback – Controls whether progression updates are broadcast to all online players.
- generation – Sets the generation type: SERIAL (one chunk at a time) or SEMI_PARALLEL (multiple chunk generation tasks created, but still serial at the engine level).
- semi_parallel_task_count – How many parallel tasks to start. A value of 0 uses the number of processor cores.
- delays.print – Time in seconds between status prints.
- delays.save – Time between automatic save events.
When using semi-parallel mode, it’s highly recommended to set max-tick-time in server.properties to -1. This prevents the server from crashing because the tick time temporarily exceeds the default limit while chunks are being generated.
Commands and Usage
Basic Command Syntax
All pre-generation is controlled through the /pregen command. Here is a quick reference:
/pregen list– Lists all active pre-generation tasks./pregen gen <dimension> start <block|chunk> <center> <radius> [<force>]– Creates a new task. The center and radius can be specified in blocks or chunks. The optional force flag (true/false) determines whether already generated chunks are regenerated; if omitted, it defaults to false./pregen gen <dimension> resume– Resumes a paused task for that dimension./pregen gen <dimension> pause– Pauses the task./pregen gen <dimension> cancel– Cancels the task for that dimension./pregen clear– Cancels all pre-generation tasks./pregen sendFeedback– Shows whether progression feedback is enabled./pregen sendFeedback <true|false>– Enables or disables feedback (generation start and finish messages are always shown).
When using block coordinates, the mod rounds down the center to the nearest chunk border and rounds the radius up to a multiple of 16. For example, /pregen gen minecraft:overworld start block 100 150 2001 will internally convert to chunk center x=96, z=144, and a radius of 2016 blocks. Using chunk coordinates gives you more direct control: /pregen gen minecraft:overworld start chunk 6 9 126 sets the area precisely.
Understanding the Progress State
During generation, the mod outputs progress messages in the format A B/C (D%) E chunks/s, where:
- A – Dimension name.
- B – Number of chunks generated so far.
- C – Total chunks to generate.
- D – Completion percentage.
- E – Chunks per second generated since the last status message.
This feedback helps you estimate how long the task will take and whether the generation speed is acceptable.
Advanced Settings and Tips
The semi-parallel mode can dramatically speed up generation on multi-core machines, but remember that Minecraft itself still processes chunks one at a time. The mod simply queues more generation work so the engine stays busy. Always test with a small radius first to gauge performance. If you plan to use a world border, pre-generate slightly beyond it to account for player movement right at the edge. Also, consider running pre-generation overnight or during maintenance windows to avoid impacting active players.
Because tasks are saved and resumed after restarts, you can safely stop the server and continue later without losing progress. Just issue a pause command before shutting down to ensure a clean state, though the mod handles unexpected stops gracefully.
Conclusion
The World Pre Generator mod is an essential tool for any server administrator who wants to deliver a lag-free exploration experience. By shifting the heavy lifting of chunk generation to a controlled, offline process, you protect your server’s tick rate and keep players immersed in the game. With straightforward commands, flexible configuration, and the ability to pick up where you left off, it fits neatly into any Minecraft setup. Whether you’re running a small community server or a large modded network, pre-generating your world is one of the simplest and most effective performance optimizations you can make.