Minecraft Java EditionWhich Java Version to Choose for Your Minecraft Server?
Complete guide to choosing the right Java version for your Minecraft server. Java 8, 17, 21? Find the right version based on your jar and mods.
Last updated: March 2026
Is your Minecraft server crashing on startup? Getting an error like Unsupported class file major version or Java 17 is required? In 90% of cases, it's a Java version problem.
Minecraft is coded in Java, and each game version requires a specific Java version to run. Using the wrong version = guaranteed crash.
In this guide, we'll explain exactly which Java version to use for your server.
📊 Java / Minecraft Compatibility Table
| Minecraft Version | Minimum Java | Recommended Java | Notes |
|---|---|---|---|
| 1.0 – 1.11 | Java 8 | Java 8 | Legacy versions, do not use Java 17+ |
| 1.12 – 1.16.4 | Java 8 | Java 8 or 11 | Most Forge 1.12 mods require Java 8 |
| 1.16.5 | Java 8 | Java 11 or 16 | Transition — Java 8 works but 11+ recommended |
| 1.17 – 1.17.1 | Java 16 | Java 16 or 17 | First major change — Java 8 no longer works |
| 1.18 – 1.20.4 | Java 17 | Java 17 | Mojang requires Java 17 minimum |
| 1.20.5 – 1.21+ | Java 21 | Java 21 | Since 1.20.5, Java 21 is mandatory |
- Minecraft 1.16 and before → Java 8
- Minecraft 1.17 → Java 16 or 17
- Minecraft 1.18 to 1.20.4 → Java 17
- Minecraft 1.20.5+ → Java 21
🔧 What About Frameworks?
Your framework (Paper, Forge, Fabric...) may also require its own Java version, sometimes newer than the Minecraft minimum.
| Framework | Minecraft Version | Recommended Java |
|---|---|---|
| Paper / Purpur | 1.18+ | Java 21 (recommended by Paper since 2024) |
| Paper / Purpur | 1.17 | Java 17 |
| Spigot | 1.18+ | Java 17 minimum |
| Forge | 1.12.2 | Java 8 only |
| Forge | 1.16.5 | Java 8 |
| Forge | 1.18 – 1.20.4 | Java 17 |
| Forge / NeoForge | 1.20.5+ | Java 21 |
| Fabric | 1.18 – 1.20.4 | Java 17 |
| Fabric | 1.20.5+ | Java 21 |
Some older modpacks (RLCraft, Pixelmon 1.12) require Java 8 even if newer Java versions exist. Always check the modpack requirements.
❌ Common Java Errors
Unsupported class file major version 65
→ You're using a jar compiled for Java 21 but your server is running Java 17 or lower. Solution: Switch to Java 21.
java.lang.UnsupportedClassVersionError
→ Same issue — the jar needs a newer Java version. Solution: Check the table above and adjust your Java version.
Error: A JNI error has occurred
→ Java version conflict. Often caused by Java 8 on a 1.17+ server. Solution: Update Java.
Server starts but crashes immediately
→ If you see Java 17 is required to run this version or similar in the logs, the message is clear: wrong Java version.
Solution: Change the version in your panel settings.
🛠️ How to Change Java Version on Lordhosting?
In short: go to Startup → change the Docker Image → restart. Done in 30 seconds.
🤔 Java 17 or Java 21? Which One to Choose in 2026?
If your server supports Java 21, choose Java 21. Here's why:
| Java 17 | Java 21 | |
|---|---|---|
| Support | LTS, end of support 2029 | LTS, end of support 2031 |
| Performance | Good | Better (~5-15% faster) |
| Garbage Collector | G1GC / ZGC | Improved ZGC (fewer lag spikes) |
| 1.20.5+ compatibility | ❌ No | ✅ Yes |
Java 21 brings notable performance improvements for Minecraft servers, including a more efficient garbage collector that reduces micro-freezes (lag spikes).
If you're on 1.18 – 1.20.4, Java 21 also works and offers better performance than Java 17. Paper officially recommends it.
📋 Quick Summary
| Your situation | Java Version |
|---|---|
| Modpack 1.12.2 (RLCraft, Pixelmon...) | Java 8 |
| Server 1.16.5 Forge | Java 8 |
| Server 1.16.5 Paper/Spigot | Java 11 or 16 |
| Server 1.17 | Java 17 |
| Server 1.18 – 1.20.4 | Java 17 (or 21 for better performance) |
| Server 1.20.5+ / 1.21+ | Java 21 |
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