
ChunkyFast
ChunkyFast is a high-performance chunk pregenerator for Paper 1.21.x. It provides a clean, predictable workflow for pregenerating terrain, supports…
⬇ Download on ModrinthChunkyFast
ChunkyFast is a high-performance chunk pregenerator for Paper 1.21.x. It provides a clean, predictable workflow for pregenerating terrain, supports running multiple world jobs in parallel, and includes built-in scheduling and load control.
Key Features
- Async chunk generation using Paper’s async chunk API
- Multi-world pregeneration: run jobs for multiple worlds at the same time
- Global scheduler: shared budgets across all active jobs so load does not scale linearly with the number of worlds
- MSPT-based limiter: dynamically adjusts throughput to keep average tick time near your configured target
- Region-friendly traversal: chunk iteration optimized for better region (.mca) locality
- Optional skipping of already-generated chunks using region header scanning (fast, non-blocking)
- Auto-save + auto-resume: job state is persisted and can resume after restart
- MiniMessage formatting for all plugin messages
Supported Versions
- Paper: 1.21.x
- Java: 21+
Installation
- Download the latest release from GitHub Releases.
- Put
ChunkyFast.jarinto your serverplugins/folder. - Start the server once to generate the default config.
- Adjust
plugins/ChunkyFast/config.ymlif needed. - Use the commands below.
Commands
Main command: /chunkyfast
Aliases: /cf, /cfast
Start pregeneration
All coordinates and radii are in CHUNKS (not blocks).
/chunkyfast start <world> circle <radiusChunks> [centerX centerZ]
/chunkyfast start <world> square <radiusChunks> [centerX centerZ]
/chunkyfast start <world> rect <minX> <minZ> <maxX> <maxZ>
/chunkyfast start <world> worldborder
How ChunkyFast Differs From Chunky
ChunkyFast and Chunky aim at the same outcome (pregenerating terrain), but they emphasize different things.
ChunkyFast focuses on
- Multi-world parallel jobs with a global scheduler
- MSPT-driven throughput control (limiter adjusts workload to keep tick time stable)
- A lean workflow with minimal overhead
- Optional non-blocking “already generated” detection via region header scanning
Chunky focuses on
- A long-established, highly feature-rich pregeneration ecosystem
- Extremely broad configuration and safety controls
- Mature workflows for a wide variety of server environments
Practical takeaway: ChunkyFast is built around multi-world scheduling and MSPT-based control, while Chunky is a feature-complete, widely adopted solution with deep tooling and history.
Notes
- Pregeneration speed is typically limited by CPU world generation and disk I/O for region writes.
- For best results, run pregeneration when the server has enough resources available.
- Edition: Minecraft Java
- File type: .jar
- Minecraft versions listed: 1.21, 1.21.1, 1.21.2
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on Modrinth — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
- Ships as ChunkyFast-1.0.0.jar — drop this file into the mods folder
- Download size: 1.8 MB
- Download link checked 30 Aug 2026 — working
These come from our own check of the pack file, not from the source page.