NapNodes
Free tool

Which Java do I need for Minecraft?

Type your server's version or paste the error you get when starting it, and we'll tell you which Java to install.

Minecraft version or the console error

Or pick one

Minecraft 1.21.1 needs

Java 21 or newer

On your PC: install Eclipse Temurin 21 from adoptium.net and check it with java -version.

NeoForge 1.21.1 server, ready in the panel (in Spanish)

Fabric 1.21.1 server, ready in the panel (in Spanish)

At NapNodes you don't install anything: when you pick the type and version in “Mods & plugins” → “Server type”, the panel sets the right Java.

Create your free Minecraft server

Minecraft and Java versions at a glance

Minecraft 26.1 and laterJava 25
Minecraft 1.20.5 to 1.21.xJava 21
Minecraft 1.18 to 1.20.4Java 17
Minecraft 1.17 and 1.17.1Java 16 · Java 17 works too.
Minecraft 1.16.5 and earlierJava 8 · With Forge and mods from that era, exactly Java 8: with a newer one they often fail on startup.

Frequently asked questions

Which Java does Minecraft 1.21 need?

Java 21 or newer, like every version since 1.20.5. From 26.1 (March 2026), Java 25.

What does “class file version 65.0” mean?

That what you're starting was built for Java 21 and your Java is older. The maths: 52 is Java 8, 61 is Java 17, 65 is Java 21 and 69 is Java 25 (the version minus 44).

Can I use a newer Java than it asks for?

From 1.17 on, usually yes. Before that, and above all with Forge, stick to exactly Java 8: with a newer one they often fail on startup with “Unsupported class file major version”.

What if I have several Java versions installed?

The server uses the first one it finds. To choose one, put its full path in the start script instead of just “java”.

Going deeper (in Spanish): how to create a Minecraft server, how to update its version and Paper, Fabric, Forge or NeoForge.

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