---
title: "How to change your Minecraft server's Java version"
url: https://help.endercloud.in/docs/how-to-change-your-minecraft-servers-java-version
category: "Minecraft Hosting"
type: Guide
tags: ["java", "minecraft", "panel", "startup"]
keywords: "java version, temurin, corretto, graalvm, unsupported class version, unsupportedclassversionerror, class file version 69, class file version 65, java 25, java 21, java 17, java 8, startup tab, docker image, requires running the server with java, change java version, which java version, java 25 minecraft, wrong java version, java version error, update java"
difficulty: beginner
time: "2 minutes"
updated: 2026-11-14
source: Endercloud Knowledge Base (official)
---

# How to change your Minecraft server's Java version

> The Versions tab picks the right Java for you. If a server still needs a specific Java (Java 25 for 26.1+, Java 21 for 1.20.5–1.21.11), choose it in Startup → Docker Image.

Every Minecraft version needs a minimum Java version. If Java is too old, the server stops right away with an error like `UnsupportedClassVersionError` or "requires running the server with Java 25 or above".

> **Note:**
> **Most people never need to change Java.** When you install software from the **Versions** tab, the correct Java is selected automatically. For example, a fresh Paper 26.3 server runs on Java 25 by itself, even though **Java 21 Temurin** is labelled "(Default)" in the Docker Image list. Change it by hand only for a custom jar, an uploaded server pack or an older modpack that needs a specific Java.

## Which Java version do I need?

| Minecraft version | Java version |
| --- | --- |
| 26.1 and newer (26.1, 26.2, 26.3…) | **Java 25** |
| 1.20.5 – 1.21.11 | Java 21 |
| 1.18 – 1.20.4 | Java 17 (Java 21 also works on most 1.20.x servers) |
| 1.17 – 1.17.1 | Java 16 or 17 |
| 1.12 – 1.16.5 | Java 8 or 11 (modded servers usually need Java 8) |
| 1.11.2 and older | Java 8 |

In 2026 Mojang switched to year-based version numbers, so 26.1 came after 1.21.11. Newer Java versions usually also run older Minecraft from 1.18 on, but mods and older Forge versions can be strict, so match the table when in doubt. Velocity and other proxies have their own requirements; check their download page.

## Steps

1.  Click **Stop** in the Game Panel.
    
2.  Open the **Startup** tab (under CONFIGURATION).
    
3.  Open the **Docker Image** dropdown and choose the Java version from the table. The list has **Java 25**, **Java 21** (Temurin, GraalVM or Corretto), **Java 19** (Corretto), **Java 17**, **Java 11** (Temurin, GraalVM or Corretto) and **Java 8** (Temurin or Corretto). Temurin, Corretto and GraalVM are different builds of the same Java; if unsure, pick Temurin.
    
4.  Click **Start** and watch the **Console**. The server should get past the point where it failed before.
    

Installed a new version and it fails with a Java error? Installing it again from the **Versions** tab (with **Wipe Server Files** off) should also select the right Java again.

## Reading the error

The error often names a "class file version". It tells you which Java the server needs:

-   `class file version 69.0` → Java 25
    
-   `class file version 65.0` → Java 21
    
-   `class file version 61.0` → Java 17
    

The other number in the message is the Java version you are running now.

> **Tip:**
> Mods and plugins built for old versions may also need updating after a Java change. If one of them fails, update it from the **Plugins** or **Mods** tab.

## Frequently asked questions

**Q: Do my players need to change Java too?**

No. The official Minecraft launcher includes the right Java for players. This setting only affects your server.

**Q: Should I always pick the newest Java?**

For Minecraft 26.1 and newer, use Java 25. For older versions, pick the version in the table. Very old Forge versions and some old mods break on newer Java.

The rest of the Startup tab is explained in [Startup settings and Docker image](/docs/startup-settings-and-docker-image). Still stuck? See [Minecraft server won't start](/docs/minecraft-server-wont-start) or [open a ticket](https://billing.endercloud.in/tickets/create) with the error from the console.