Dupe Key

This mod adds a key bind to dupe the mod is from 1.21-1.21.11

8.8K Downloads

fabricutility

Rent Server with this Mod

Screenshots

About this Mod

Item Duper
Dupe items directly from a simple GUI — no commands needed.
Press K (configurable) to open the Item Duper menu. Hold any item in your main hand and click Dupe Item to instantly duplicate it into your inventory.
Features

🎮 Simple and clean GUI
⌨️ Keybind to open the menu (default: K)
📦 Copies full item data — including Shulker Box contents (Creative mode)
✅ Works in Creative mode (full NBT copy)
✅ Works in Survival/Adventure with OP permissions (via /give)
🔁 Compatible with Minecraft 1.21 – 1.21.11

How to use

Hold the item you want to duplicate in your main hand
Press K to open the menu
Click Dupe Item
Done!

Notes

In Creative mode, items are duplicated with full data (enchantments, NBT, Shulker Box contents)
In Survival/Adventure, requires OP or cheats enabled — item data will be transferd when u use the mod 2.0.0 or higher

Requirements

Fabric Loader ≥ 0.15.0
Fabric API
Minecraft 1.21 – 1.21.11

Available Versions

Dupe Key 1.0.0release

MC 1.21, 1.21.1, 1.21.2, 1.21.3, 1.21.4, 1.21.5, 1.21.6, 1.21.7, 1.21.8, 1.21.9, 1.21.10, 1.21.11, 26.1fabric

March 27, 2026

Dupe Key 1.0.0release

MC 1.21, 1.21.1, 1.21.2, 1.21.3, 1.21.4, 1.21.5, 1.21.6, 1.21.7, 1.21.8, 1.21.9, 1.21.10, 1.21.11fabric

March 21, 2026

How to Install Dupe Key on Your Server

Order Server

Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).

Set fabric Loader

In the panel under "Egg", select the fabric loader and matching Minecraft version (26.1).

Install Mod

Open the mod browser in the dashboard and search for "Dupe Key". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.

Compatibility

Mod Loaders

fabric

Minecraft Versions

26.1, 1.21.11, 1.21.10 (+10 more)

Server-side

✗ Unsupported

Recommended RAM

4 GB(min. 3 GB)

Frequently Asked Questions

Dupe Key server crashes on startup – what to do?

Most common cause: wrong fabric version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (26.1). You can switch loaders with one click in the panel.

Is Dupe Key compatible with fabric?

Dupe Key officially supports fabric for Minecraft 26.1, 1.21.11, 1.21.10. The Mado dashboard automatically detects incompatible loader combinations.

Server lagging with Dupe Key – how to optimize performance?

Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if Dupe Key consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.