Slatetune

SpawnTune

Summary

Fine-tune natural mob spawning with searchable toggles, per-mob limits, category caps, and global scaling.

Description

SpawnTune gives you precise control over natural mob spawning without requiring commands or manual JSON editing.

Features

• Search and browse every naturally spawning mob type.
• Enable or disable natural spawning for individual mobs.
• Set per-mob population limits for each dimension.
• Configure the caps used by vanilla spawn categories.
• Scale all category caps with one global multiplier.
• See the effective category cap after scaling.
• Restore vanilla category caps or double the configured caps with one click.
• Save settings from an in-game screen provided through Mod Menu.
• Use cached per-tick entity counts to avoid repeated full scans during spawn checks.
• Save configuration atomically to reduce the risk of empty or partially written files.

Requirements

• Minecraft Java Edition 1.21.11
• Fabric Loader 0.18.0 or newer
• Fabric API
• Java 21
• Mod Menu is optional but recommended for opening the configuration screen.

Install SpawnTune on the server or integrated singleplayer server that controls spawning. Installing it only on a multiplayer client does not change server-side spawning.

Configuration

• ON / OFF: Allows or blocks natural spawning for that mob.
• Per-mob cap: Sets the maximum loaded population in each dimension. Use -1 for no custom per-mob limit and 0 to block spawning.
• Category cap: Replaces the vanilla capacity for a spawn category. Use -1 to keep the vanilla value.
• Global multiplier: Multiplies every effective category cap from 0 to 100.

The effective category cap is calculated as:

configured or vanilla category cap x global multiplier

Very high caps can create large numbers of entities and severely reduce server performance. Increase values gradually.

Scope

SpawnTune controls vanilla natural chunk spawning. It does not remove mobs that already exist, and it does not change mobs created by commands, breeding, structures, or mob spawners.

Support

When reporting a problem, include the Minecraft version, Fabric Loader version, Fabric API version, SpawnTune version, and the relevant log or crash report.