Universal ClearLag

Universal ClearLag is a lightweight server utility for reducing unnecessary entity load and giving server owners direct control over cleanup and mob spawning across multiple Minecraft versions.

Supported versions currently include:

• Forge 1.6.4
• Forge 1.7.10
• Forge 1.8.9
• Forge 1.12.2
• Forge 1.16.5
• Forge 1.18.2
• Forge 1.20.1
• NeoForge 1.21.11

Originally focused on dropped-item cleanup, ClearLag now includes configurable mob cleanup, live configuration reloading, spawn prevention, administrative cleanup commands, and in-game spawn-control tools.

Features

• Automatic dropped-item cleanup
• Automatic configurable mob cleanup
• Cleanup countdown warnings
• Configurable cleanup intervals
• Manual cleanup commands
• Configurable mob spawn prevention
• Vanilla and modded entity support
• Live JSON configuration reloading
• /clearlag reload for manual configuration reloads
• Spawn Control Tool for quickly blocking or allowing future spawning of targeted mobs
• Saved mobs are protected from spawn-prevention rules when loaded back from disk
• Low-overhead runtime entity and spawn checks

Spawn prevention affects future spawn attempts rather than deleting existing mobs. Existing entities remain in the world unless removed through a cleanup command or scheduled cleanup policy.

ClearLag is designed to keep its own overhead low. Configuration is validated and compiled when loaded, runtime spawn checks use cached entity rules, and loaded entities are only scanned when an actual cleanup occurs.

Manual Entity Cleanup

On Minecraft 1.6.4 through 1.12.2, ClearLag provides an administrative entity-removal command:

/clearlag clear entities

Specific entity types can also be targeted.

Examples:

/clearlag clear entities Slime
/clearlag clear entities Zombie Skeleton

Minecraft 1.12.2 uses namespaced registry IDs:

/clearlag clear entities minecraft:slime

The legacy /clearlag entities clear command spelling is also supported.

Manual entity clearing is intentionally separate from scheduled cleanup rules and can remove loaded non-player living entities including slimes, villagers, golems, named mobs, tamed mobs, bosses, and supported modded entities.

Players, armor stands, dropped items, projectiles, and nonliving utility entities are excluded.

On Minecraft 1.16.5 and newer, manual entity clearing is deprecated in favor of Minecraft's more powerful vanilla /kill selectors. Automatic ClearLag cleanup remains fully supported.

Server-Side Use

Universal ClearLag is designed to remain server-side-only by default.

The Spawn Control Tool is disabled by default, meaning clients do not normally need ClearLag installed.

All cleanup, spawn prevention, commands, countdowns, and configuration features continue to work entirely server-side.

If the Spawn Control Tool is enabled:

• Most supported versions use a marked vanilla item and remain compatible with server-only installation.
• Minecraft 1.7.10 retains the original registered ClearLag tool for compatibility, which requires matching clients and a server restart when enabled.

Configuration

ClearLag uses JSON configuration files and supports live reloading.

Most configuration changes can be applied without restarting the server using:

/clearlag reload

Existing explicit settings are preserved during upgrades, including spawn-control tool settings and entity policies.