Anti Chat Lag eliminates the game freeze that occurs when sending chat messages on offline-mode (cracked) servers. It does this by preventing the client from attempting to generate a chat message signature, which is the root cause of the lag.

📦 Installation

Install Fabric Loader for Minecraft 1.21.11.
Place the downloaded .jar file into your .minecraft/mods folder.
No other mods or configuration are required.

This mod is client-side only. The server does not need it — offline-mode servers already accept unsigned messages.

✨ Features

Instant chat, no freezes — Messages send immediately without blocking the game thread.
Zero configuration — The fix is active as soon as the mod is installed.
Lightweight implementation — A single mixin that cancels ClientPacketListener.setKeyPair().
Keeps everything else intact — All other chat features (formatting, commands, etc.) continue to work normally.

🧩 Compatibility

Minecraft	Loader	Status	Version
1.21.11	Fabric	✅ Supported	1.0.0

Required dependencies: None (not even Fabric API).
Known incompatibilities: None known. The mod only touches chat signing initialisation and should be compatible with other chat-related mods and server plugins.
Works alongside: Sodium, Iris, Lithium, and other performance mods without issues.

❓ FAQ

Does this need to be installed on the server?
No. The lag is caused by the client trying to sign messages when no valid authentication keys exist. Installing it on the server has no effect.

Will this break chat on online-mode servers?
No. On online-mode servers where proper Mojang authentication is in place, messages are still signed normally. The mod only prevents the signing setup from blocking the game when it would fail.

Is it safe to use on any server?
Yes. Offline-mode servers already accept unsigned messages. This mod simply stops the client from wasting time trying to produce a signature that isn’t needed.

Can I include this in my modpack?
Absolutely. You may use Anti Chat Lag in any Modrinth or CurseForge-hosted modpack with attribution.

🐛 Reporting Issues

If you encounter any problems, please open an issue on the issue tracker. Include your Minecraft version, modloader, and a log file if available.

💖 Support the Project

This mod is free and open source. If you find it useful, you can support its development:

📝 Source & License

Anti Chat Lag is licensed under the MIT License.
Source code: github.com/Sekai0NI0itamio/ModItamio/tree/main/mods/antichatlag
Author: Itamio — Contributor: Asd1281yss