About Backpack Plus: Sophisticated Backpacks Addon
From ModrinthAllow Sophisticated Backpacks to exceed the default limits of 144 inventory slots and 10 upgrade slots via config, which means you can even have a backpack with 1,440 item slots!
Sophisticated Backpacks is a great mod, but even if you tweak the inventory slot count in its config file, it caps at 144 — which might not be enough for some players. Inspired by The Fool modpack, this addon uses Mixin to significantly raise the config limits for both inventory slots and upgrade slots. Now, you can have an ultra-large backpack!
First, you need to launch the game once to activate this mod. After that, you'll notice that the inventory slot limit in sophisticatedbackpacks-server.toml is no longer capped at 144. Also, changes to the backpack's inventory slot count will only apply to newly obtained backpacks. 
Warning: Do not stuff too many items into an ultra-large backpack — this may lead to severe lag, crashes, or potential world corruption. Use with caution!
Highlights
From source dataGame versions
Built for Minecraft 1.21.1.
Loaders
Runs on NeoForge.
Footprint
Rated a light load on a server.
What kind of mod it is
From the catalogWeapons, items & crafting
New weapons, gear, items and the recipes to make them.
Runs on your server
From source side supportModrinth lists Backpack Plus: Sophisticated Backpacks Addon as required on the server. Check its Modrinth page to see whether players need it too.
Compatibility
- Game
- Minecraft
- Loaders
- NeoForge
- Runs on
- Serverrequired on the server
- Game versions
- 1.21.1
Verified at the source
- ✓ModrinthOfficial listing, checked 2026-10-01Open ↗
- ✓AuthorHakujoucho, as published on Modrinth
- ✓LicenseLicenseRef-All-Rights-ReservedFree
