FatStack
by Octal
FatStack changes the maximum stack size of items on a Fabric server, and the limits are set in a config file the server owner can edit.
What it does
On first start the mod creates a config file with default values, and the server owner can change the default maximum stack size for items there. Changes take effect after the config is reloaded. The mod runs only on the server, and the new limits are sent to connected clients, which are notified of the changes, so players join without installing anything. Files are published for Fabric, for 1.21.9 and 1.21.10, with 1.1 for 1.21.10 as the latest file, under the Mozilla Public License 2.0, and the mod is open source.
Key features
Configurable stack sizes
Maximum stack sizes for items can be set in a config file, replacing the vanilla defaults.
Generated config on startup
A config file with preset defaults is created automatically the first time the server starts.
Client notification
Connected clients are told about the changed stack limits, so the server does not need a client-side install.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
How it compares
Stack Size Tweaks is open source under the MIT License and runs client and server on Fabric and NeoForge for 1.21 – 26.3. One Stack Size is a client and server Fabric mod for 1.20 – 1.21.1 under All rights reserved. Data Driven Stack Sizes is server-side only on Fabric for 1.21 – 1.21.4 and is not open source.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| FatStack | Fabric | 1.21.9 – 1.21.10 | Server-side only | 2025-10-19 |
| Stack Size Tweaks | Fabric and NeoForge | 1.21 – 26.3 | Client and server | 2026-09-25 |
| One Stack Size | Fabric | 1.20 – 1.21.1 | Client and server | 2025-06-02 |
| Data Driven Stack Sizes | Fabric | 1.21 – 1.21.4 | Server-side only | 2025-03-15 |
In the catalog
FatStack is one of 8,016 Management mods on ModsFinder, and one of 5,930 Management mods for Fabric. 15,569 mods support Minecraft 1.21.10.
More from Octal
Similar mods
What the author says
FatStack adds a config file to change the default max stack size for all items. At startup it'll generate a config file with a set of defaults, and that config file can be changed to change the default max stack size of any item.
Official listing
- Modrinth page
- modrinth.com/mod/fatstack
- Owner
- Octal
- Published
- 2025-10-06
- Updated on Modrinth
- 2025-10-19
- Facts verified
- 2026-10-15