How do I install StackUpper?

Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. Download the .jar. Put it in the .minecraft/mods folder and launch that loader profile. Opens on CurseForge — not every file is mirrored on our own servers.

What Minecraft version does StackUpper work with?

The listing gives Minecraft 1.21.9, 1.21.10, 1.21, among others. This is the version stated by the author or source site, not something we verified ourselves.

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StackUpper

Java mod listed for Minecraft 1.21. Downloads from the MC Java Mods app on Android.

by Maikokain · on CurseForge

Which Minecraft do you have?

Every version of the game needs its own build. Pick yours, then download — the wrong build installs fine and then does nothing in the game. This mod is built for NeoForge only.

Minecraft 1.21.9–1.21.10Newest
Minecraft 1.21.6–1.21.8
Minecraft 1.21.3–1.21.5
Minecraft 1.21.2
Minecraft 1.21–1.21.1

⬇ Download for 1.21.9–1.21.10 ⬇ Download for 1.21.6–1.21.8 ⬇ Download for 1.21.3–1.21.5 ⬇ Download for 1.21.2 ⬇ Download for 1.21–1.21.1

I don't know my version or loader

Open the Minecraft launcher and look at the profile you play on — it names both, like fabric-loader-1.21.4. The version also shows in the bottom-right corner of the game's main menu.

No loader in the profile name? Then it's plain Minecraft, and these mods won't run — you need Fabric or NeoForge installed first.

Open in MC Java Mods Get it on Google Play →

A NeoForge mod that allows changing item stacksize up to 2^31-1, with custom rules.

Scripting

https://github.com/MaiKokain/StackUpper/wiki/Scripting

Note

Any incompatibility open an issue in GitHub or join the Discord

Quick facts

Edition: Minecraft Java
File type: .jar
Minecraft versions listed: 1.21.9, 1.21.10, 1.21
How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
Where to get it: Opens on CurseForge — not every file is mirrored on our own servers.

Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.

File checked by MCModsHub

Ships as StackUpper-2.1.0-26.1.jar — drop this file into the mods folder
Download size: 362 KB
Download link checked 27 Sept 2026 — working

These come from our own check of the pack file, not from the source page.

Explore more

All Mods for Java All Minecraft Java mods Java mods for 1.21