LagReducer — dynamic distances, safe clearing, and smart entity caps for Paper 1.21.8
Keep TPS high without gutting gameplay. LagReducer dynamically lowers a player’s view/simulation distance only while they’re moving fast, periodically clears clutter with safety guards, and caps entity counts per-chunk with precise, configurable rules.
Why use LagReducer?
- Smooth performance: Reduce client/server load only when it matters (elytra/flying/vehicles/high speed).
- Safe cleanup: Configurable warnings, blacklists, and name exemptions protect valuables and pets.
- Hard caps where you need them: Per-chunk totals, categories, and per-type limits with a limiter blacklist.
Features
- Dynamic Distance (per-player)
- Lowers view and simulation distance while: flying, gliding, in vehicles, or exceeding a speed threshold (blocks/sec).
- Auto-restores distances after slowing down (with hysteresis and minimum switch delay).
- Honors a bypass permission for staff/testing.
- Clear Items & Entities
- Automatic timed clearing with broadcast warnings (customizable times).
- Category toggles: items, living entities, XP orbs, projectiles, misc.
- Blacklists for item materials and entity types.
- Optional “exempt named entities” to protect pets and named mobs.
- Entity Limiter (per-chunk)
- Limits for total, items, living, monsters, animals, ambient.
- Per-entity-type caps (e.g., ZOMBIE: 12).
- Limiter blacklist: completely ignore certain types (don’t count them and never cancel them).
- Ignore selected spawn reasons (e.g., CUSTOM, COMMAND, SPAWNER_EGG).
- Debug logging option.
Commands
- /lagreducer reload — Reload config and restart features
- /lagreducer clear — Run an immediate clear
- /lagreducer status — Show feature toggles and clear interval
Alias: /lr
Permissions
- lagreducer.admin — Use reload/status and admin functions
- lagreducer.clear — Allow manual clear command
- lagreducer.bypass.distance — Exempt player from dynamic distance changes
Config at a glance
- Dynamic distance tuning:
- sampleTicks, speedThresholdBps, restoreHysteresisFactor, minSwitchMillis
- fastViewDistance, fastSimulationDistance, consider: flying/gliding/vehicles
- Clearer safety:
- warnAtSeconds, exemptNamedEntities
- entityBlacklist, itemBlacklist
- Entity limiter controls:
- perChunk: total/items/living/monsters/animals/ambient (set -1 to disable a cap)
- perType: per-entity-type caps
- blacklist: types ignored entirely by the limiter
- ignoreSpawnReasons, debug
Example config snippet
dynamicDistance:
enabled: true
sampleTicks: 10
speedThresholdBps: 12.0
restoreHysteresisFactor: 0.7
minSwitchMillis: 1500
fastViewDistance: 6
fastSimulationDistance: 4
consider: { flying: true, gliding: true, vehicles: true }
clearer:
enabled: true
intervalSeconds: 600
warnAtSeconds: [60, 30, 10, 5, 3, 2, 1]
exemptNamedEntities: true
categories: { items: true, living: true, xpOrbs: true, projectiles: false, misc: false }
entityBlacklist: [ARMOR_STAND, ITEM_FRAME, PAINTING]
itemBlacklist: [NETHER_STAR, DRAGON_EGG, SHULKER_BOX]
entityLimiter:
enabled: true
blacklist: [ARMOR_STAND, ITEM_FRAME, PAINTING]
perChunk:
total: 150
items: 80
living: 100
monsters: 60
animals: 60
ambient: 20
perType: { ZOMBIE: 12 }
ignoreSpawnReasons: [CUSTOM, SPAWNER_EGG, COMMAND]
debug: false
Compatibility and requirements
- Server: Paper 1.21.5+ (and compatible forks)
- Java: 21
- No NMS, API-only; safe across minor patches.
- No external dependencies.
Installation
- Drop LagReducer.jar into plugins/
- Start the server to generate config
- Edit plugins/LagReducer/config.yml
- Use /lagreducer reload to apply changes
Notes
- Set any limiter value to -1 to disable that specific cap.
- Blacklists protect entities/items from clearing or limiting.
- Works alongside most optimization plugins; avoid running multiple “clear lag” plugins at once to prevent conflicts.
