As featured in:

This snapshot mostly contains tweaks and bug fixes, but there are also some new technical additions such as a separate simulation distance slider and an increased thread count (no I'm not talking about the fancy sheets you're thinking about buying).

Oh, and you also seemed to enjoy Strongholds quite a lot, so we decided to add them back into the game. Enjoy!

How to install

  • Download the Minecraft Java Edition Installer.
  • Run the Installer. (If you get an installation error download Java)
  • Open the Minecraft Launcher and click on the "Installations" tab.
  • In Versions, check the box next to Snapshots.
  • Select Latest Snapshot and press Play.

Snapshots can corrupt your world, so please backup and/or run them in a different folder from your main worlds.

What's New:

Have a random snapshot! In this snapshot, we've replaced the random number generator used for world generation, which makes more seeds come out as different... but it also moves everything around in the world, so expect all worlds to look different in this snapshot.

Another thing that we've replaced is the cubemap - the spinning image that you see behind the main menu. It's pretty sweet!

Also, in case you missed it, we're having our annual Minecraft Live event this Saturday. Make sure to check that out!

We still highly recommend backing up your world before loading it in this snapshot.

Changes in 21W41A

  • The main menu backdrop now shows a Caves & Cliffs: Part II scene
  • Badlands mineshafts generate higher up
  • Geodes now only generate up to height 30 and their rarity has been adjusted to match 1.17 levels
  • The angle at which sprinting against a block does not break your sprint has been increased a bit

Technical Changes in 21W41A

  • Changed the prioritization order of the chunk rendering pipeline
  • Unrendered chunk holes in the world should not appear anymore while flying fast with a high render distance
  • Server classes are now signed
  • New random number generator for Overworld generation

Fixed Bugs in 21W41A

  • MC-118134 Item frame texture as an item uses texture of oak planks
  • MC-137950 Signs textures does not correspond to the actual texture of their handle
  • MC-142385 Campfire texture has one pixel extending into hotbar outline
  • MC-148182 The zombie villager "profession" texture uses villager-skin-colored pixels
  • MC-152506 Wither skull projectile has faces with old texture
  • MC-160256 Texture of door items does not match the blocks
  • MC-166508 Glitchy chunk rendering since 1.15 pre-release 2
  • MC-173339 Comparators lit base texture is incorrect
  • MC-203155 Enchanting table GUI uses old lapis texture
  • MC-225949 Parity Issue: different Bedrock and Java sign items textures.
  • MC-227398 Misplaced pixel on cave vines texture
  • MC-230302 Glow Item Frame item texture is missing two pixels
  • MC-236620 Nether biomes don't generate correctly
  • MC-236650 Minecraft in 1.18 has 2^48 seeds instead of 2^64 seeds.
  • MC-237330 Worlds created with seed "REDApRES" (0) crash when trying to load new 1.18 mountain biomes / java.lang.NullPointerException: Cannot invoke "dfw.a(double, double, double)" because "this.a" is null
  • MC-237457 Snowy Slopes biome no longer generates stone cliff feature from experimental snapshots
  • MC-238003 Stone in jagged peaks is always covered by snow blocks
  • MC-238561 Axolotls aren't able to spawn at all in lush caves (recurrence of MC-218701)
  • MC-238661 InhabitedTime value/Local Difficulty doesn't increase

Previous release notes

Known Issues in 21W38A

This snapshot is still not compatible with older worlds – to play in this snapshot, you will have to create a new world

World saving can sometimes take a very long time – if you see the world stop moving for a time, this is why

Changes in 21W38A

  • Sprinting is no longer reduced to walking when gently brushing your sleeve against a wall
  • Fixes for the distribution of ores

ORE Distribution

  • Copper ore generates up to y 95 (as originally designed)
  • Increased the amount of copper
  • Lapis lazuli generates in blobs, like other ores (instead of spread out)


  • Previously, any collision with a block would reduce sprinting to walking. Now, for very minor angles of collision with a block, players retain their sprint. For larger angles of collision, the old behavior is retained.

Technical Changes in 21W38A

  • A new setting has been added: “Simulation distance”
  • Maximum amount of background threads increased
  • Added telemetry for world loading

Simulation Distance Setting

  • Entities will not be updated outside of simulation distance.
  • Allows higher render distance with less CPU load.
  • A new slider in video settings on the client.
  • A new simulation-distance property in dedicated server properties.
  • We will continue working on it with a goal of simulation distance also affecting block and fluid ticking.

Maximum Amount of Background Threads Increased

Various background tasks including worldgen are executed on a background thread pool. Its size equals the amount of available CPU threads minus one, but there was an upper limit of 7. Now this upper limit is 255. This should help higher-end machines with world-gen performance.

The upper limit can be overridden by Java system property, for example when running multiple servers on a single machine.


In this release, we are re-introducing diagnostic tracking, which was part of Minecraft: Java Edition until 2018. We are bringing it back to better understand our players and to improve their experience. Specifically, we hope to ensure stronger performance for the extremely heavy world generation in the second part of the Caves & Cliffs update later this year.

In practice, this can mean identifying technical pain points in the game, like how less powerful hardware performs in high-complexity terrain. This information will also help us prioritize various aspects of development, balance game features (by learning, for instance, that the goats are pushing every single player off the cliffs) and lend new Minecrafters a helping hand (after realizing that many of them get stuck at the same points). All data is treated according to GDPR and CCPA best practices and is used to develop a better-performing and generally more enjoyable Minecraft: Java Edition.

At this point the only implemented event is world load.

World Load Event

  • Sent when loading singleplayer world or connecting to multiplayer server
  • Contains following information:
    • launcher identifier
    • user identitifer (XUID)
    • client session id (changes on restart)
    • world session id (changes per world load, to be reused for later events)
    • game version
    • operating system name and version
    • Java runtime version
    • if client or server is modded (same information as on crash logs)
    • server type (single player, Realms or other)
    • game mode

Fixed Bugs in 21W38A

  • MC-44055 - Game fails to switch the audio output from one device to another after the game has started (from title screen)
  • MC-236611 - No sound for using shears on weeping, twisting, cave vines or kelp
  • MC-236618 - Strongholds don’t generate in 21w37a
  • MC-236621 - Liquids sometimes do not propagate
  • MC-236633 - Random light level of 0 in sky
  • MC-236656 - Crash when changing render distance / java.lang.ArrayIndexOutOfBoundsException: Index 28084 out of bounds for length 26136
  • MC-236665 - Memory leak in 21w37a
  • MC-236698 - Big Spruce Trees don’t generate in Groves
  • MC-236711 - Starting and stopping JFR profiling multiple times within the same minute overwrites previous JFR results saved during that minute
  • MC-236718 - Dripstone caves generate above the ground
  • MC-236795 - Cannot start with alternate JVM due to JFR requirement
  • MC-236873 - Problems with JFR event metadata
  • MC-236967 - Too many aquifers on biome surfaces at Y=63 and below
  • MC-237109 - Aquifers often generate with harsh straight borders