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Input Optimizer

Near-zero client input latency.

Fabric
Loaders
Fabric
Downloads on Modrinth
45.5K
Followers on Modrinth
23
versions
8
Updated
August 20, 2026Aug 20
Published
in 2026
Comparison · swipe

At a glance

Runs on Fabric
For Minecraft 1.21.11–26.2
Client only — no need to install it on the server
Latest version — 1.2.0-mc26.2 from August 20, 2026
License LGPL-3.0-only — free
Where it's needed
In gamerequiredOn servernot needed

Install in the game only; not needed on the server

Game versions1.21.11–26.2

Kemmlow's Input Optimizer

Logo

Kemmlow's Input Optimizer is a client-side Fabric mod that reduces the delay between your physical mouse and keyboard inputs and the game registering them.

What It Does

Logo

Minecraft processes mouse and keyboard input later in the frame cycle than it needs to. This mod corrects that by reading input earlier, feeding fresher data into the vanilla input pipeline, and aligning input consumption to the correct point in the render cycle.

On Windows, Linux, and macOS the mod bypasses the standard GLFW input layer and reads directly from OS level input APIs. This is the lowest level a mod can access without writing a device driver. The result is that input from your physical device reaches the game faster and through fewer intermediate layers.

Keyboard input timing is also improved on all platforms. This is not something comparable mods currently address.

The vanilla mouse smoothing algorithm is left completely intact. The mod changes nothing about how input feels.

What It Does Not Do

This mod does not affect rendering performance or framerate. It does not change mouse sensitivity, combat mechanics, or any data visible to servers. It does not remove or alter vanilla mouse smoothing. No configuration is needed or available. The mod works automatically on launch.

Why Download It

If input responsiveness matters to you in any context, whether that is PvP, building, speedrunning, or general play, this mod reduces the gap between your physical input and the game acting on it. It does this without changing any gameplay behavior and without requiring any setup.

Platform Support

Out of the box support is provided for Windows, Linux, and macOS, including the full set of lower level OS input API improvements. Partial support is provided for Android based Minecraft launchers, where limited input timing improvements apply. On any other platform the mod loads and falls back gracefully without causing issues.

Critical Information Before Downloading

This mod is client side only. Servers do not need to install it and will not detect any change. The mod does not affect any server visible behavior. Vanilla mouse smoothing is fully preserved.

Known Incompatibilities

FAQ

Is this client side only? Yes. Servers do not need to install anything.

Does this increase FPS? No. This mod does not touch rendering performance.

Does this change how the mouse feels? No. Vanilla smoothing is completely preserved.

Does this affect servers or other players? No. All changes are local to the client input path only.

Will it work on my system? Out of the box support is provided for Windows, Linux, and macOS. Partial support is provided for Android based launchers. The mod falls back gracefully on any other platform.

License

LGPL-3.0-only Copyright (c) Kemmlow

FAQ

How to install Input Optimizer?

Install Fabric for your Minecraft version, download Input Optimizer for the same version and loader, put the file into the mods folder and launch the game with the loader profile.

Which Minecraft versions does Input Optimizer support?

Input Optimizer has builds for Minecraft 1.21.11–26.2.

Is Input Optimizer needed on the server?

Client only — no need to install it on the server

License and source
GNU Lesser General Public License v3.0 onlyfree to use and share; changes to the mod itself must be published under the same license
Original — Modrinth↗Files unchanged, verified with SHA-512Is this your mod? For rights holders

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