What is Chunky?
Chunky by pop4959 pre-generates world chunks so terrain creation happens once and on your schedule, rather than as lag spikes while players explore. It ships as a mod for Fabric, Forge, and NeoForge and as a plugin for Paper-family servers, with identical commands everywhere.
Server owners run it before opening a map; single-player worlds benefit before long elytra journeys or Distant Horizons setups.
Commands and Workflow
The standard pre-generation session:
/chunky center 0 0
/chunky radius 5000
/chunky start
- /chunky pause and /chunky continue manage long runs (progress persists across restarts).
- /chunky progress reports completion percentage and rate.
- Shapes: squares, circles, and custom shapes via
/chunky shape; per-dimension runs by switching worlds with/chunky world. - /chunky trim deletes chunks outside a radius — useful before enlarging borders or resetting outlands.
- WorldBorder pairing: set the vanilla or Chunky border to the pre-generated radius so players never outrun prepared terrain.
Expect pre-generation to run for hours on big radii; run it overnight, ideally with C2ME (Fabric) accelerating generation. Server CPU sits near full load by design — schedule accordingly.
Chunky FAQ
How long does Chunky take?
Proportional to area and hardware: a 5,000-block radius is millions of chunks and commonly runs several hours. The progress command estimates completion; runs resume automatically after restarts.
Does pre-generation help FPS or TPS?
TPS primarily: generation is one of the heaviest server tasks, and removing it during play eliminates the classic exploration lag spikes. Clients also feel smoother chunk delivery.