Features:
- Rewrites Minecraft’s random systems around Java 17 LXM generators
- Replaces the slower CheckedRandom and related generators
- Targets structure placement and world generation
- Also covers feature and carver placement
- Client side changes for details such as dropped items
- Patches the MC-239059 bug
- Only the slower vanilla generators are targeted
- Can be installed on the client or the server alone
- Needs a JVM with full Java 17 RandomGenerator support
- Worldgen stays close to vanilla apart from some cave shapes
- Fabric and Quilt support
- For Minecraft 1.21.1
Faster Random is an optimization mod that rewrites the random number systems Minecraft leans on. Instead of the game’s own CheckedRandom and the generators built around it, it uses the LXM generators introduced in Java 17, which take a little longer to construct but are quicker at producing numbers afterwards. Because the game reuses many of its generators, that construction cost is often avoided.
The work is aimed at the places where the game asks for randomness in bulk. Structure placement, world generation, and feature and carver placement are the main targets, and the client picks up smaller changes in places like dropped items. Only the slower vanilla generators are touched, and a long-standing vanilla bug, MC-239059, is patched along the way. How much you actually gain is situational and depends on your system, since a faster chunk pipeline soon runs into memory and storage limits.
World generation stays almost identical to vanilla, with the exception of some cave shapes, so a world made with it is not suited to parity-sensitive play such as speedrunning. The mod does not need to be present on both sides of a connection, it wants a JVM that fully supports the Java 17 RandomGenerator system and disables itself otherwise, and it sits comfortably next to other terrain optimization mods.
The project is archived, and it is now recommended mainly for worlds that were already generated with it so their terrain keeps matching. At 0.02 MB it remains one of the smallest additions you can make to a Fabric or Quilt setup on Minecraft 1.21.1.
