ModsJava
UltraAFK: Anti-Lag & Optimizer
Java mod listed for Minecraft 1.21–26.x. Downloads from the MC Java Mods app on Android.
A lightweight, high-performance anti-lag and optimization plugin for Paper 1.21.3+. Stops lag machines, stacks XP orbs, and keeps your server TPS at a…
⬇ Download on Modrinth
Tired of griefers dropping your server's TPS to single digits with piston loops or arrow machines? UltraAFK is a lightweight, no-nonsense optimization plugin built for Paper that handles the heavy lifting so you don't have to. No bloat, no crazy dependencies. Just pure performance.
🚀 Features
- Next-Gen In-Game GUI: Manage everything on the fly using
/uafk menu. Features a modern Dialog API interface on 1.21.7+ (with seamless transitions and direct input forms) and a classic Chest GUI fallback for older versions. - Anti-Lag Machine Protection: Automatically freezes malicious piston loops (with a configurable cooldown), blocks soul sand + arrow lag machines, and limits snowball spam per chunk.
- Smart Item Clear: Cleans up ground items only when farms overflow. It calculates the actual amount of items (not just stacks) so your server stays clean without deleting valuable player drops.
- XP Orb Stacker: Groups XP orbs within a 12-block radius using spatial hashing to drastically reduce entity ticking lag.
- Smart AI Freeze: Stops mob AI near AFK players to save resources. It safely ignores named/tamed mobs and won't freeze mobs near active players.
- Fast Travel Protection: Smoothly scales down velocity for Elytra and Ice Boats if a player exceeds a certain blocks-per-second limit, preventing chunk generation lag.
🛠️ Commands & Permissions
| Command | Description | Permission |
|---|---|---|
/uafk reload |
Reloads the configuration file. | ultraafk.admin |
/uafk menu |
Opens the interactive settings GUI. | ultraafk.admin |
/uafk |
Shows plugin info. | None |
⚙️ Requirements & Compatibility
- Server Software: Paper (or forks like Purpur).
- Minecraft Versions: 1.21.3 up to 26.3+ (Single universal JAR).
- Java Version: Java 21+ (Runs perfectly on Java 25 servers).
- Note: This plugin uses asynchronous pipelines and synchronous entity scans to ensure maximum performance without breaking the Paper API rules.
Quick facts
- Edition: Minecraft Java
- File type: .jar
- Minecraft versions listed: 1.21, 1.21.1, 1.21.10
- 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 Modrinth — 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 UltraAFK-1.1.1.jar — drop this file into the mods folder
- Download size: 73 KB
- Download link checked 8 Nov 2026 — working
These come from our own check of the pack file, not from the source page.