Lag control that adapts instead of panicking.
GrimLag is a lag-aware, adaptive performance management plugin for Paper servers.
It doesn’t spam clears, doesn’t nuke farms on sight, and doesn’t pretend lag is the players’ fault. It watches the server, decides how bad things really are, and responds accordingly.
Think damage control, not scorched earth.
GrimLag continuously monitors server performance and shifts between four internal stages:
HEALTHY – Everything runs normally
WARNING – Light intervention begins
DEGRADED – Aggressive but fair throttling
CRITICAL – Survival mode
No hard switches. No instant punishment. The server eases into restrictions and eases back out.
When lag spikes, mob AI is selectively disabled to reduce CPU load.
When performance recovers, AI is restored automatically.
Mobs don’t stay brain-dead forever.
This isn’t a museum.
Spawner output is dynamically scaled based on current lag stage.
Spawners slow down under load
Resume normal behavior when the server recovers
No global “off switch” rage-quits
GrimLag limits entity overpopulation per chunk, not globally.
Soft caps first
Hard caps only when needed
Players are never removed
Priority entities survive longer
Crowded chunks get handled without killing activity across the entire world.
Redstone activity is dampened using probabilistic throttling during lag spikes.
Redstone still works
It just doesn’t fire every single tick when the server is on fire
Less lag, fewer broken contraptions
This is intentional sabotage. But polite.
Instead of nuking dropped items:
Items are merged where possible
Old items age faster under lag
Only then are excess items removed
Your server gets cleanup — not an extinction event.
Instead of nuking dropped items:
Items are merged where possible
Old items age faster under lag
Only then are excess items removed
Your server gets cleanup — not an extinction event.
As performance improves, GrimLag reverses its own restrictions:
AI returns
Spawners normalize
Redstone resumes full behavior
Despawn rules relax
Nothing stays throttled longer than necessary.
Adapt, don’t panic
Throttle, don’t nuke
Recover automatically
Be predictable, not aggressive
GrimLag is built for long-running survival servers, not short-lived benchmarks.
Paper (recommended)
Java 17+
