LagFixer — plugin for optimizing, increasing TPS and fixing lag in Minecraft

LagFixer — plugin for optimizing, increasing TPS and fixing lag in Minecraft

LagFixer is a server plugin for Minecraft that reduces TPS load through a set of targeted optimization modules. Unlike similar solutions, each source of lag is treated separately: mobs, dropped items, redstone, explosions, moving entities, and tree leaves. The admin only enables the modules that are actually needed for a specific server and configures them according to their load profile. 

Plugin modules

Each module is placed in a separate YAML file and works independently. This allows for targeted response to problems without side effects on vanilla mechanics.

MobAiReducer

Replaces the standard mob AI with its own optimized behavior. Removes heavy pathfinders — constant looking around, aimless head movements, and reaction to other players within the line of sight. On a server with farms of 200+ animals, this gives the biggest TPS boost among all modules. Has separate toggles for animals, monsters, villagers, tamed, and flying entities.

A cow farm with frozen bodies that activate upon player hit

EntityLimiter

Sets an entity cap per chunk: separately for animals and monsters (15), separately for drops, moving entities (3), and projectiles (5). The whitelist — villager, wither, ender dragon, wolf, cat, zombie villager — the limit does not affect them. 

LagShield

A dynamic "fuse". Monitors TPS in real time and disables specific mechanics when it drops below thresholds. For example: mob spawning, projectiles, explosions, and others. 

WorldCleaner

A periodic auto-cleaner. Every 600 seconds (10 minutes) it removes dropped items older than 10 seconds, hostile mobs from its list (zombie, skeleton, creeper, spider, phantom, fish, squid), and projectiles. Warns players 15, 10, 5, 4, 3, 2, and 1 seconds before running.

A special feature is Abyss. Removed items do not disappear forever, but go into a temporary chest from which they can be taken back via /abyss. The inventory closes 60 seconds after opening.

Server cleanup message and its successful execution

RedstoneLimiter

Protects the server from overloaded circuits. Limits: 1100 redstone ticks per chunk per second and 50 piston movements. When exceeded, the plugin blocks updates or breaks the causing block — the behavior is configured separately. Adds a 1500 ms cooldown to levers, buttons, and redstone torches — protection against auto-clickers.

A separate blacklist for blocks that cannot be pushed by a piston. By default, it includes sand, red sand, and gravel — this blocks the most common dupes.

ExplosionOptimizer

Controls explosion power and chain reactions. You can set the maximum radius separately for TNT, minecarts with TNT, creepers, fire charges, wither skeleton skulls, and end crystals. Chains are configured in pairs: TNT does not ignite neighboring TNT, crystals do not blow each other up, creepers — at the admin's discretion. A maximum of 3 explosions in one chain, with a cooldown of 1000 ms between them.

For extreme cases, complete disablement of explosions is provided, retaining only the sound and optional damage without breaking blocks.

InstantLeafDecay

Makes leaf decay instant after chopping down a tree. The radius from the trunk is up to 7 blocks. Optionally enables dropping items (saplings, apples, sticks).

VehicleMotionReducer

Optimizes collision handling for boats and minecarts. Optionally removes minecarts with chests from generated mineshafts — useful for servers where chunks are often generated for the first time.

AbilityLimiter

Limits spamming with the elytra booster and trident with the Riptide enchantment. Cooldown: 5 seconds for elytra, 3 seconds for trident. Additionally removes 5 durability points from the item upon each use — it will be harder for the player to load chunks through fast travel.

ConsoleFilter

Filters console messages using regular expressions. Removes spam about connecting/disconnecting, chat, command execution, "Save complete", and timeouts. Standard patterns are already written, optionally saves filtered lines to a separate log.

Commands and placeholders

The main command is /lagfixer (aliases /lf, /antilag, /lag). 

Output of the /lagfixer monitor command in the game chat

Conclusion

LagFixer specifically optimizes individual sources of load on the server — from mob AI to redstone, without interfering with vanilla game mechanics. Suitable for survival servers with 30+ online players, projects with large animal farms, and situations where the admin already knows their server's TPS profile and wants flexible control instead of a standard approach.