StackMob Fabric
by VoxelBuster
StackMob Fabric lets players combine large numbers of mobs into a single entity, which reduces the load that many separate mobs place on the game.
What it does
Stacked mobs are grouped under one entity, so a crowd of identical mobs counts as one for the game to track. The mod is meant for mob farms and crowded areas, where a large number of separate mobs slow the server down. Players can keep farms running while the number of entities stays low.
Installation needs Fabric API, Cardinal Components API and Cloth Config API. Mod Menu is optional and adds a settings screen for the mod's options. Since the environment is client and server, both the server and every player need the mod. The license is GNU General Public License v3.0 or later, and the code is open source. Files are published for Fabric for 1.20.4 – 1.21.3, with 1.2.2 for 1.21.1 as the latest file.
Key features
Mob stacking
Nearby mobs of the same kind merge into one entity that holds their count.
Lag reduction
Fewer tracked entities lighten the load on the server, especially in large farms.
Farm compatibility
Stacked mobs keep working with mob farms, so spawning and drops are not blocked.
Configurable options
Cloth Config API provides a settings screen, which Mod Menu can open from the mod list.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Requirements
Dependencies declared by the latest file for each loader.
Required 3
Optional 1
Use cases
Mob farms on a server
Server owners run large farms without the entity count growing with each mob.
Who it’s for: Server owners and players who run large mob farms or live in crowded areas. The mod is also useful for anyone who wants fewer separate entities on a busy world.
How it compares
One Stack Size is Fabric only for 1.20 – 1.21.1, with All rights reserved and no open source code, so it is not an open source option. IG: Item Clumps is open source under the GNU Lesser General Public License v3.0 or later, works on Fabric for 1.20.1 – 26.3 and runs on client and server, but it groups items rather than mobs. Item Limiter is client-side only and not open source.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| StackMob Fabric | Fabric | 1.20.4 – 1.21.3 | Client and server | 2025-04-02 |
| One Stack Size | Fabric | 1.20 – 1.21.1 | Client and server | 2025-06-02 |
| IG: Item Clumps | Fabric | 1.20.1 – 26.3 | Client and server | 2026-10-04 |
| Item Limiter | Fabric | 1.19 – 1.21.6 | Client-side only | 2026-01-13 |
Questions
Does StackMob Fabric need to be installed on the server?
Which dependencies does StackMob Fabric require?
Which game versions does StackMob Fabric support?
In the catalog
StackMob Fabric is one of 3,545 Optimization mods on ModsFinder, and one of 2,575 Optimization mods for Fabric. 13,252 mods support Minecraft 1.21.3.
Similar mods
What the author says
A mod that allows players to stack massive amounts of mobs into a single entity. Reduces lag without breaking mob farms. Inspired by Nathat23's StackMob 5 for Spigot.
Official listing
- Modrinth page
- modrinth.com/mod/stackmob-fabric
- Owner
- VoxelBuster
- Published
- 2024-04-20
- Updated on Modrinth
- 2025-04-02
- Facts verified
- 2026-10-15