What is Krypton?
Krypton by astei (lead developer of the Velocity proxy) rewrites Minecraft's Netty networking pipeline with the optimizations proven in high-scale proxy software: better buffer handling, cheaper packet flushing, and micro-optimized encryption and compression.
It is a Fabric mod for clients and especially servers, where dozens of connected players multiply every saved allocation.
What It Changes
- Flush consolidation: packet flushes batch together per tick, cutting syscall overhead substantially under player load.
- Optimized varint and packet encoding reduces per-packet CPU.
- Reduced allocation churn in the network layer lowers GC pressure alongside mods like FerriteCore.
- No protocol changes: vanilla clients connect to Krypton servers and vice versa; it is invisible on the wire.
Where it fits: every Fabric server benefits a little, busy ones benefit a lot. On clients the gain is smaller but real during chunk-heavy scenes. Forge-ecosystem equivalents of its ideas ship inside other server-perf mods, so Krypton itself stays Fabric-only.
Krypton FAQ
Is Krypton server-side or client-side?
Both work; the server sees the larger benefit. No pairing requirement exists between the two sides.
Does Krypton work with Forge?
No, it is Fabric-only. Forge servers get comparable networking tweaks from broader server-performance mods instead.