LagFixer

LagFixer is a Minecraft server plugin that fights tick lag by throttling the mechanics that usually cause it, mob pathfinding, entity counts, explosions, and heavy redstone clocks, instead of turning gameplay features off outright. It runs on Bukkit, Spigot, Paper, Purpur, and Folia from 1.13.2 through 26.2, and its current builds need Java 21. It will not fix lag caused by a badly configured server or poorly coded plugins on its own, but it noticeably cuts the load a vanilla-heavy world puts on the tick loop.

What LagFixer optimizes

LagFixer is split into independent modules, each targeting one common source of tick lag. Every module can be toggled and scoped to specific worlds in its config file, except ConsoleFilter, which only applies globally.

• MobAiReducer: replaces mob movement and pathfinding to cut CPU cost, aimed at large animal or mob farms.
• EntityLimiter: caps how many entities can stack up in a single chunk.
• LagShield: watches server load and adjusts settings automatically during a latency spike.
• ExplosionOptimizer: limits explosion power and chain reactions from TNT, creepers, and end crystals.
• ItemsCleaner: clears old dropped items on a timer, with an /abyss command so players can recover ones removed by mistake.
• RedstoneLimiter: shuts down redstone clocks that run fast enough to threaten server stability.
• VehicleMotion: optimizes boats and minecarts, and removes chest minecarts that spawn in mineshafts.
• AbilityLimiter: throttles rapid trident and elytra use that forces excessive chunk loading.
• ConsoleFilter: hides selected console spam to keep logs readable.

Installation and requirements

Installing LagFixer follows the usual steps for any server plugin: drop the jar into the plugins folder on a Bukkit, Spigot, Paper, or Purpur server, or the Folia build on a Folia server, then restart. LagFixer has no listed dependencies, so no other plugin needs to be installed first.

Commands, permissions, and configuration

The main command opens an in-game menu for toggling modules, and it answers to /lagfixer, /lf, /antilag, or /lag, gated behind the lagfixer.command permission node. The /abyss command lets a player retrieve an item ItemsCleaner removed. Each module lives in its own block in the config file with an enabled switch and a worlds list, so a server can run MobAiReducer everywhere but limit RedstoneLimiter to a single redstone-heavy world.

Compatibility and integrations

LagFixer publishes a matching build for every target it supports, so Folia gets a dedicated build rather than the same jar as Bukkit and Spigot, and that Folia build currently ships through a beta release channel rather than a full release. LagFixer exposes its own PlaceholderAPI placeholders for TPS, MSPT, CPU and memory use, and entity counts, so a scoreboard or tab list plugin can display them directly. The project also lists WildStacker, UltimateStacker, RoseStacker, and LevelledMobs as plugins it can work alongside for stack and mob management. For a closer look at where server tick time actually goes, spark profiles individual methods rather than reporting a single TPS number.