Which Java Does Minecraft Need?

Minecraft 26.3 needs Java 25. Older versions need older Java: find your Minecraft version in the table below.

Java version for each Minecraft version

Minecraft versions	Java needed	Releases
26.1 to 26.3	Java 25	5
1.20.5 to 1.21.11	Java 21	14
1.18 to 1.20.4	Java 17	13
1.17 to 1.17.1	Java 16	2
1.0 to 1.16.5	Java 8	66

From Mojang's official version files, checked Nov 8, 2026. See every release on the Minecraft versions page.

How to install the right Java

Find your Minecraft version in the table and note the Java number.
Download that Java version from a trusted OpenJDK build such as Eclipse Temurin (Adoptium) or Microsoft Build of OpenJDK. Pick your system (Windows, macOS or Linux) and the JDK or JRE installer.
Run the installer. On Windows, tick the option to set JAVA_HOME and add Java to PATH if it is offered.
Open a new terminal and type java -version. The first line should show the version you installed.
For servers, start with the full path to that Java if you have several installed, for example "C:\Program Files\Eclipse Adoptium\jdk-25…\bin\java.exe" -jar server.jar.

Questions

Do I need to install Java to play Minecraft?

Usually not. The official Minecraft Launcher downloads the right Java for you. You only need to install Java yourself to run a server, a modded launcher setup, or a server .jar file.

Why does my server say 'UnsupportedClassVersionError'?

Your installed Java is older than the version that Minecraft release needs. Install the Java version shown in the table for your Minecraft version and start the server with it.

Can I use a newer Java than required?

Often yes for the game itself, but some older mods and plugins only work on the Java version their Minecraft version was built for. When in doubt, use the version in the table.