Item Duper
by aditdpride47
Item Duper, a Fabric magic mod for 1.21.11, adds a late-game machine setup that duplicates items placed in its chest.
What it does
A player builds an Item Duper machine from a crafted Unfinished Item Duper, finished with a Dragon Egg and End Crystals. Obsidian music discs are part of the correct build, and the duplication only starts once the setup is complete. Items placed inside the Item Duper Chest are copied automatically by the second machine.
If the chest fills past capacity, the machine throws out its contents and blows up, so running it on automation is risky. The mod describes the duplication as an end-game reward. Its recipes call for rare materials such as Dragon Eggs, End Crystals, music discs, redstone blocks and netherite scrap, which makes the factory expensive by design.
The mod is published for Fabric only, for 1.21.11, and runs on the client and the server, so both need it. The code is not open source; the mod is released under All rights reserved.
Key features
Unfinished Item Duper
The machine starts as an unfinished block that is completed with a Dragon Egg and End Crystals.
Item Duper Chest
Items placed in this chest are duplicated automatically once the second machine is built correctly.
Overfill explosion
Once the chest overflows, the device spits out everything inside and detonates, making automated use a gamble.
Rare build materials
The recipes use Dragon Eggs, End Crystals, obsidian music discs, redstone blocks and netherite scrap.
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Late-game item production
Players who have finished the rest of the progression can use the factory to multiply rare items they have already gathered.
Who it’s for: The mod suits players in later stages of survival or multiplayer worlds who have access to Dragon Eggs and End Crystals and want a costly, high-risk duplication setup.
Questions
Does Item Duper need Fabric API?
Does Item Duper have to be installed on a server?
What happens if the Item Duper Chest is overfilled?
In the catalog
Item Duper is one of 7,216 Magic mods on ModsFinder, and one of 3,630 Magic mods for Fabric. 19,862 mods support Minecraft 1.21.11.
Similar mods
What the author says
Item Duper adds a powerful late-game duplication factory to Minecraft. Craft the Unfinished Item Duper using End Crystals and the Dragon Egg, finish the machine with obsidian and music discs, then build the correct setup: Item Duper -> Pole -> Item Duper Chest. Items placed inside the Item Duper Chest duplicate…
Official listing
- Modrinth page
- modrinth.com/mod/item-duper
- Owner
- aditdpride47
- Published
- 2026-07-27
- Updated on Modrinth
- 2026-08-01
- Facts verified
- 2026-10-15