Minecraft Snapshot 25w42a Server Jar Download
Also known as snapshot, pre-release, release candidate.
Minecraft Snapshot 25w42a is a weekly development snapshot of Minecraft: Java Edition leading up to 1.21.11, published by Mojang on 14 Oct 2025. Its dedicated server jar is 56.1 MB and requires Java 21 or newer. The final Minecraft 1.21.11 was released on 9 Dec 2025.
Download
Download server.jar56.1 MB
Downloads from piston-data.mojang.com — Official — Mojang.
- SHA-1 · published by Mojang
d9c6cfd4ba84f5080206259d2563f75796f14470
How to verify this file on Windows, macOS and Linux.
Version facts
| Published by Mojang | |
|---|---|
| Channel | Preview (weekly) |
| Required Java | Java 21 or newer · Temurin 21 |
| File size | 56.1 MB |
| Licence / terms | Minecraft EULA |
| Upstream project | www.minecraft.net |
What changed
Full changelog for Minecraft Snapshot 25w42a (Minecraft Wiki)Compatibility
No plugins or mods — the unmodified game exactly as Mojang ships it (data packs still work).
Players need a Minecraft: Java Edition Snapshot 25w42a client on the same version.
Minecraft Snapshot 25w42a in other server software
Known issues & safety notes
- Preview builds are experimental: they can corrupt or irreversibly upgrade worlds, and most plugins and mods do not support them yet. Test on a copy of your world.
How to set up Minecraft Snapshot 25w42a
- Install Java 21 or newer (e.g. Eclipse Temurin) and check it with
java -version. - Download
server.jarfrom Mojang (button above) into an empty folder. - Start it once with the script below; it creates
eula.txtand stops. - Set
eula=trueineula.txtto accept the Minecraft EULA, then start again. Players join on port25565.
Linux / macOS — start.sh
#!/bin/sh
# start.sh — Minecraft 25w42a
cd "$(dirname "$0")"
JAVA_MAJOR=$(java -version 2>&1 | awk -F'"' '/version/ {split($2, v, "."); print (v[1] == "1") ? v[2] : v[1]}')
if [ "$JAVA_MAJOR" -lt 21 ] 2>/dev/null; then
echo "Java 21 or newer is required (found Java $JAVA_MAJOR)."
exit 1
fi
java -Xms4G -Xmx4G -jar server.jar nogui
Windows — start.bat
@echo off REM start.bat — Minecraft 25w42a REM Needs Java 21 or newer: run "java -version" to check. java -Xms4G -Xmx4G -jar server.jar nogui pause
Rule of thumb: 2–4 GB for a few friends, 6–10 GB for a public server with plugins. Set -Xms equal to -Xmx and leave 1–1.5 GB for the operating system. How much RAM?
Docker
docker run -d -p 25565:25565 -e EULA=TRUE -e TYPE=VANILLA -e VERSION=25w42a --name mc itzg/minecraft-server
Uses the community itzg/minecraft-server image, which downloads the file itself.
Upgrading
FAQ
What Java version does Minecraft Snapshot 25w42a need?
Minecraft Snapshot 25w42a needs Java 21 or newer. Running it on an older Java fails with an UnsupportedClassVersionError mentioning class file version 65.0.
Is Minecraft Snapshot 25w42a safe for my survival world?
Only on a copy. Preview versions are experimental and upgrade worlds irreversibly; keep a backup and don't switch a live world to a snapshot, pre-release or release candidate.
Is this the Minecraft game or an APK?
No. This is the Java Edition dedicated server — software for hosting a world. It is not the game client and there is no Android APK. Phone and console players use Bedrock Edition.