Which Java does Minecraft need
Java 8, 17 or 21: which version for which Minecraft, why the game complains about Java and how to never think about it.
Different Minecraft versions need different Java. That's the classic error — you installed one Java and the game wants another.
Which for which
- Minecraft up to 1.16.5 — Java 8.
- 1.17 — Java 16.
- 1.18–1.20.4 — Java 17.
- 1.20.5 and newer — Java 21.
In TCLauncher
There's nothing to install: the launcher downloads the right Java for every game version and keeps several side by side. A 1.12.2 build starts with Java 8, a 1.21 build with Java 21.
If you want your own Java, set it in the build settings.
Java errors
- “Unsupported class file major version” — Java is too old.
- Old Forge won't start on new Java — it needs Java 8.
Download TCLauncher — it's free.
FAQ
Do I need to install Java for TCLauncher?
Not for the Windows version — Java is bundled, and the launcher downloads it for the game itself.
Can I have several Java versions?
Yes, the launcher keeps them apart and picks the right one for each game.