
Undo
A Minecraft Fabric mod that lets players undo world actions with a single key press. Supports reverting block placements, breaks, and state changes like doors and trapdoors.
About this Mod

Undo Mod — Introduction
A powerful and stable Undo/Redo mod for Minecraft Fabric.
About Undo Mod
Undo Mod provides full Undo and Redo functionality for Minecraft Creative mode players. Whether you misplaced a block, demolished a build by accident, or want to compare different designs — go back to a previous state with a single keypress.
Core Features
- Undo / Redo — Supports block placement, breaking, and state changes (trapdoors, levers, buttons, etc.)
- Cascade Reaction Capture — Chain reactions triggered by block changes (falling sand, vine growth, redstone updates, piston pushes) are bundled into a single undo operation
- BlockEntity NBT Restoration — Chest contents, furnace progress, brewing stand recipes, and more are fully restored
- HUD Display — Real-time display of undoable/redoable action counts
Operation Modes
| Mode | Description |
|---|---|
| Block Only | Records only block operations — ideal for builders, leaner history |
| Full | Records block + entity + inventory operations — complete scene recovery |
Getting Started
Key Bindings
| Key | Action |
|---|---|
Backspace |
Undo 1 action |
Number(1~100) + Backspace |
Undo N actions |
Shift + Alt + Backspace |
Undo all |
Enter |
Redo 1 action |
Number(1~100) + Enter |
Redo N actions |
Shift + Alt + Enter |
Redo all |
U |
Open settings |
H |
Open help |
| Mouse Back Button | Undo (must be enabled in settings) |
| Mouse Forward Button | Redo (must be enabled in settings) |
Number Input Examples
Press 5 → Press Backspace → Undo 5 actions
Press 1 → Press 0 → Press Enter → Redo 10 actions
Press Backspace directly → Undo 1 action (default)
Shift + Alt + Backspace → Undo all
Configuration
Without YACL (Basic)
- Press
Uto open the vanilla settings screen - Options: Mouse Side Buttons toggle, Undo Mode (Full / Block Only)
- Config file:
config/undo-client.json
With YACL (Full)
- Press
Uto open the YACL configuration screen - Additional options: HUD corner selection, history stats, usage hints
Installation
- Install Fabric Loader and Fabric API for your MC version
- Place the matching MC version JAR into
.minecraft/mods/ - (Optional) Install YACL v3 for the full config GUI, or download the
-bundledJAR - Launch the game and press
Uto configure
Dependencies
| Component | Main JAR | Bundled JAR |
|---|---|---|
| YACL v3 | Recommended (install separately) | Built-in |
| Fabric API | Required | Required |
Tech Stack
- Loader: Fabric
- Java: ≥ 21
- Build: Gradle + Fabric Loom
Available Versions
How to Install Undo 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 (26.1.2).
Install Mod
Open the mod browser in the dashboard and search for "Undo". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.
Compatibility
Mod Loaders
Minecraft Versions
26.1.2, 1.21.2, 1.21.1
Server-side
✓ RequiredRecommended RAM
4 GB(min. 3 GB)Frequently Asked Questions
Undo 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 (26.1.2). You can switch loaders with one click in the panel.
Is Undo compatible with fabric and quilt?
Undo officially supports fabric, quilt for Minecraft 26.1.2, 1.21.2, 1.21.1. The Mado dashboard automatically detects incompatible loader combinations.
Server lagging with Undo – how to optimize performance?
Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if Undo 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.
Similar Mods
Rent Modded Server
Install Undo with just one click on your server.
Details
- License
- Creative Commons Attribution Non Commercial Share Alike 4.0 International
- Server-side
- Required