Stack Manager (Fabric/NeoForge)
by Neni-o
Stack Manager lets a server owner change how many of each item fit in one stack, by editing a config file that covers vanilla and modded items alike.
What it does
Stack Manager generates a config file that lists items from vanilla and from installed mods, each with a maximum stack size that the owner can change. Per-item limits are edited in that file, and newly installed mods are added automatically at startup or reload. Keys are full item IDs in the form namespace:item, and every value is clamped to a range of 1 to 99 when the config loads, since a network cap of 99 avoids protocol and NBT problems. Potions are handled separately, since their effect type is stored in NBT.
The mod is server-side only, so players join without installing anything and the server alone needs it. Setups that suit it include raids and boss fights, where fewer inventory trips mean less time spent sorting. Files exist for Fabric and NeoForge across 25 release versions, 1.18.2 – 1.21.11, released under the MIT License. The mod is not open source. Single-player worlds can use it by placing the jar in the mods folder.
Key features
Per-item stack limits
Each item's maximum stack size is set in the generated config, and changes take effect after a restart or reload.
Automatic detection of new items
Items from mods installed later are added to the config at startup or reload, so no entries have to be typed by hand.
Find and replace editing
The config can be edited with a find and replace pass, which speeds up changing many entries at once.
Potions stack by identical effect
Only potions with the same effect type stack together, because the effect is kept in each potion's NBT data.
Compatibility
Latest build for each game version and loader.
1.21.x12 of 12 versions with builds
1.20.x7 of 7 versions with builds
1.19.x5 of 5 versions with builds
1.18.x1 of 1 version with builds
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Who it’s for: Server owners who want to change stack sizes for vanilla and modded items on a dedicated server, and players who run single-player worlds with larger stacks.
How it compares
Stack Config is a Fabric, Forge and NeoForge mod that runs on client and server, is open source under the GNU General Public License v3.0 or later, and covers 1.18.2 – 26.2. Stackcraft is a NeoForge mod for 1.21.1 – 1.21.11 that also runs on client and server and is open source under the MIT License. Stack Manager covers the same Fabric and NeoForge range as Lenient Stack Size, but Lenient Stack Size is open source and also server-side only.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Stack Manager (Fabric/NeoForge) | Fabric and NeoForge | 1.18.2 – 1.21.11 | Server-side only | 2026-01-01 |
| Stack Config | Fabric, Forge and NeoForge | 1.18.2 – 26.2 | Client and server | 2026-10-12 |
| Stackcraft | NeoForge | 1.21.1 – 1.21.11 | Client and server | 2025-12-19 |
| Lenient Stack Size | Fabric and NeoForge | 1.21.10 – 26.2 | Server-side only | 2026-08-02 |
Questions
Does Stack Manager need Fabric API?
Does every player need Stack Manager installed?
How are new mods' items handled?
In the catalog
Stack Manager (Fabric/NeoForge) is one of 4,058 Storage mods on ModsFinder, and one of 2,474 Storage mods for Fabric. 19,862 mods support Minecraft 1.21.11.
More from Neni-o
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What the author says
A lightweight server-side mod that generates a config with all items (vanilla + modded) and lets you set the max stack size per item. Works in singleplayer (integrated server) and on dedicated servers. ## Features - Generates config/stackmanager_items.json with every registered item. - Per-item stack limits you can…
Official listing
- Modrinth page
- modrinth.com/mod/stack-manager
- Owner
- Neni-o
- Published
- 2025-09-01
- Updated on Modrinth
- 2026-01-01
- Facts verified
- 2026-10-15