Pre-generating your Minecraft world is one of the most effective ways to reduce lag on a server. When chunks are already generated, the server does not need to calculate terrain, structures, and biomes while players explore.
Why Pre-Generate?
Chunk generation is the single most CPU-intensive task on a Minecraft server. When players explore new areas, the server must:
- Calculate terrain height maps
- Generate structures (villages, temples, strongholds)
- Place ores and vegetation
- Calculate biome transitions
- Populate entities
All of this happens on the main thread, causing TPS drops and rubberbanding for all players.
Using Chunky
Chunky is the standard pre-generation plugin for Paper, Spigot, Purpur, and Fabric servers.
Installation
Download Chunky from Modrinth or SpigotMC. Place in the plugins folder and restart.
Basic Commands
/chunky center 0 0 # Set center of generation
/chunky radius 5000 # 5000 blocks from center
/chunky shape circle # Circle shape
/chunky start # Start pre-generation
/chunky pause # Pause if needed
/chunky continue # Resume
Recommended Settings
| World Size | Radius | Estimated Chunks | Time (approx) |
|---|---|---|---|
| Small server | 3,000 | ~28,000 | 30-60 min |
| Medium server | 5,000 | ~78,000 | 1-3 hours |
| Large server | 10,000 | ~314,000 | 5-12 hours |
| Massive | 20,000 | ~1,250,000 | 24-48 hours |
Run pre-generation when the server is empty or has few players.
All Three Dimensions
Pre-generate the Overworld, Nether, and End separately:
/chunky world minecraft:overworld
/chunky radius 5000
/chunky start
# Wait for completion
/chunky world minecraft:the_nether
/chunky radius 2500
/chunky start
# Wait for completion
/chunky world minecraft:the_end
/chunky radius 3000
/chunky start
After Pre-Generation
Set a world border to prevent players from going beyond pre-generated terrain:
/worldborder center 0 0
/worldborder set 10000
FAQ
Does pre-generation actually help? Yes. It eliminates chunk generation lag, which is the biggest performance bottleneck.
How long does pre-generation take? Depends on radius and hardware. A 5,000-block radius takes 1-3 hours.
Should I pre-generate before opening the server? Yes. Pre-generate, then set a world border, then open to players.
Does pre-generation use a lot of disk space? Yes. Large worlds can use 5-50 GB of storage. NVMe SSD recommended.
Related: MSPT explained, Best CPU for Minecraft server, View distance guide