FixLag is a comprehensive performance optimization plugin designed for modern Minecraft servers (Paper/Spigot 1.17+). Unlike simple "clearlag" scripts, FixLag provides a suite of reactive and proactive tools to maintain high TPS without disrupting gameplay or breaking technical farms.
- Smart Clear: Automatically triggers entity cleanups only when the server's 1-minute TPS drops below a configurable threshold (default: 16.0).
- Item Recovery System: Accidentally cleared a valuable item? Use
/fixlag retrieveto open a temporary GUI and recover entities deleted during the last cycle. - Mob Stacking: Reduces entity processing overhead by stacking similar nearby mobs into a single entity with a numeric multiplier.
- Intelligent Filtering: Configuration allows for excluding custom-named items, ensuring player-named pets or items remain safe.
- Explosion Optimizer: During low TPS, the plugin can limit the number of blocks destroyed by TNT and disable item drops from explosions to prevent cascading lag.
- Panic Mode: Temporarily freezes mob AI when TPS drops critically low (e.g., 14.0) to save CPU. AI is automatically restored once TPS recovers.
- Spawner Optimizer: Automatically pauses mob spawners from spawning new entities when server performance is low.
- Dynamic Distance: Automatically adjusts view distance and simulation distance (1.18+) in real-time based on server load.
- Overload Detection: Scans for high entity densities around players and alerts staff before the server crashes.
- Server Analytics: Detailed
/serverinfocommand showing TPS, MSPT, RAM, CPU usage, and per-world entity/chunk counts. - Redstone Analyzer: Profile and locate laggy redstone contraptions with
/fixlag checkredstone. - Chunk Analyzer: Identify "laggy" chunks with the
/fixlag checkchunkscommand, which ranks loaded chunks by entity count. - Config Optimizer: Use
/fixlag optimizeconfigto analyze yourbukkit.yml,spigot.yml, andpaper.ymlfiles. The plugin will suggest optimized values to improve performance.
| Command | Permission | Description |
|---|---|---|
/fixlag |
fixlag.command |
Manually triggers entity cleanup. |
/fixlag retrieve |
fixlag.retrieve |
Opens the GUI to recover deleted items. |
/fixlag checkchunks |
fixlag.checkchunks |
Analyzes chunks for high entity counts. |
/fixlag checkredstone |
fixlag.checkredstone |
Profile redstone activity across chunks. |
/fixlag optimizeconfig |
fixlag.optimizeconfig |
Suggests optimizations for server config files. |
/serverinfo |
fixlag.serverinfo |
Displays real-time performance stats. |
/gcinfo |
fixlag.gcinfo |
Displays JVM Garbage Collection details. |
The project is built using Java 21 and the Gradle wrapper.
Build Requirements:
- JDK 21
- Gradle 8.10 (provided via wrapper)
To build the project:
./gradlew buildThe file will be put at path/to/fixlag/build/libs/fixlag-x.y.z.jar.