This is a small client-side mod for Fabric Minecraft 1.21.11. It prevents the game from freezing or stuttering when chat messages are received or sent on servers.
In vanilla Minecraft, the game processes chat messages on the main render thread. This is the same thread that draws the game to your screen. When a message arrives, the game stops everything to do several heavy tasks:
If any of these tasks take even a few milliseconds, your game will stutter. If they take longer, your game will freeze until the task finishes.
This mod intercepts chat messages the moment they arrive and moves the heavy processing to a dedicated background thread. This allows the main game thread to continue rendering frames without interruption.
Because the processing happens in the background, you might notice a very slight delay before a message appears in your chat box, but your framerate will remain smooth and consistent.
This was only tested on offline mode I am not even sure if it's a real problem in online mode. But the processing is done same everywhere so it should work for anyone