Pre-releaseDownload Minecraft 1.21.11-pre5 Server
The Minecraft 1.21.11-pre5 snapshot server JAR, direct from Mojang. Release date, file size, checksum and Java requirement below.
Snapshot for Minecraft 1.21
Java required
Java 21
Released
Dec 3, 2025
File size
54 MB
Channel
Pre-release
SHA-1 checksum
d62fa16c3bbb5c6809cbd45cd60f3396a9d543a3
⚡ Not for a production server
Back up your world before you run this build. A snapshot can convert a world to a newer data format that an older release refuses to load, plugins and mods do not work on it, and anything in it can change or disappear in the next snapshot.
How to run a snapshot server
Exactly like any vanilla server. Put the JAR in an empty folder on its own, run it once, accept the EULA, then start it again. Keep it in a separate folder from your release server so the two never share a world.
Start script (Linux/macOS)
java -Xms2G -Xmx4G -jar server.jar noguiThe first launch stops immediately and writes an eula.txt file. Open it, set eula=true, and start the server again. That line is your agreement to Mojang's EULA and is required to run any Minecraft server.
2 GB boots a snapshot for a couple of players. For a real player count, size it with the Minecraft RAM calculator