Krypton

Krypton

A mod to optimize the Minecraft networking stack

27.0M downloads
Created Apr 9, 2026
by astei

About

Warning

Krypton is a work-in-progress. I do not provide any guarantees about its stability, compatibility with other mods, or support for every possible setup out there. Support for this mod is provided on a "best-effort" basis. This is not my day job, it is a hobby growing out of related work I've done.

Sponsor Me!

Did this mod make your server playable? Chip in a bit of money so I can continue developing it.

What's Krypton?

Krypton (from Ancient Greek kryptos, "the hidden one") is a Fabric mod that attempts to optimize the Minecraft networking stack. It derives from work done in the Velocity and Tuinity projects.

Krypton contains several optimizations, including:

  • Highly optimized Netty handlers derived from the Velocity proxy, which I am the developer of. These handlers have seen real-world usage and extensive profiling, and strategically deploy native code where it makes the most sense.
  • Flush consolidation to lower server CPU usage (and reducing the impact from hardware security vulnerabilities which exploit speculative execution) and lower server tick times.
  • Micro-optimizations to reduce memory usage and improve packet serialization speeds.

Compatibility

Krypton should work anywhere where a Minecraft can run — naturally, however, it is tuned for Linux.

I try to ensure that Krypton will work with the Fabric API, Lithium, and Sodium. Support beyond these mods is provided on a best effort basis.

Versions

v0.2.10Latest
1.21.9, 1.21.10, 1.21.11fabricOct 5, 2025

* Update for Minecraft 1.21.9

Download
v0.2.9
1.21.5, 1.21.6, 1.21.7, 1.21.8fabricMar 29, 2025

* Update to Minecraft 1.21.5 * Resync network handlers from upstream

Download
v0.2.8
1.21, 1.21.1, 1.21.2, 1.21.3, 1.21.4fabricJun 22, 2024

* Update to 1.21 (@BenCat07)

Download

Download

Download v0.2.10

Minecraft: 1.21.9, 1.21.10, 1.21.11

Loaders: fabric

Tags

fabric1.21.71.21.81.21.91.21.101.21.11