Installing Java on Windows

Minecraft Java Edition and the OptiFine installer both need a Java runtime. The official launcher bundles one for the game, but that runtime is not always registered for opening .jar files — which is why the OptiFine installer sometimes does nothing when you double-click it. Installing a standalone JRE fixes it.

Choose your OS

Pick your operating system if you'd like to switch guides:

Which Java version do I need?

• Minecraft 1.17 and newer: Java 17 or later.
• Minecraft 1.20.5 and newer: Java 21 or later.
• Older versions: Java 8 still works.

When in doubt, install the latest LTS build of Eclipse Temurin — it covers every modern OptiFine release.

1. Download a Java runtime

Download the installer for your system from adoptium.net (Eclipse Temurin) or from oracle.com.

2. Install it

Run the installer and accept the default options. A restart is not usually required.

3. Check that it works

Open a terminal or command prompt and run:

java -version

If you see a version number, Java is installed correctly.

Notes for your system

Choose the .msi installer and keep the option that associates .jar files with Java enabled — that is what makes the OptiFine installer open with a double-click.