> For the complete documentation index, see [llms.txt](https://allthemods.gitbook.io/guides/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://allthemods.gitbook.io/guides/general/java.md).

# Java

### Java Versions <a href="#java-versions" id="java-versions"></a>

| Minecraft   | Download Page                                                                                                                                  | Linux Shell Command               |
| ----------- | ---------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------- |
| **<= 1.15** | [Java 8](https://adoptium.net/?variant=openjdk8\&jvmVariant=hotspot)                                                                           | `sudo apt install openjdk-8-jdk`  |
| **1.16**    | [Java 8](https://adoptium.net/?variant=openjdk8\&jvmVariant=hotspot) OR [Java 11](https://adoptium.net/?variant=openjdk11\&jvmVariant=hotspot) | `sudo apt install openjdk-11-jdk` |
| **1.17**    | [Java 16](https://adoptium.net/?variant=openjdk16\&jvmVariant=hotspot)                                                                         | `sudo apt install openjdk-16-jdk` |
| **1.18+**   | [Java 17](https://adoptium.net/?variant=openjdk17\&jvmVariant=hotspot)                                                                         | `sudo apt install openjdk-17-jdk` |
| **1.21+**   | [Java 21](https://adoptium.net/temurin/releases/?variant=openjdk21\&jvmVariant=hotspot)                                                        | `sudo apt install openjdk-21-jdk` |

On the download page sort for your **Operating System** and your **Architecture** (This should typically be **x64**)

<details>

<summary>Other Java Download Links</summary>

[Amazon Corretto](https://aws.amazon.com/corretto/), [Azul Zulu](https://www.azul.com/downloads/?package=jdk#zulu), or [Oracle JDK](https://www.oracle.com/java/technologies/downloads/archive/)

</details>

***

### Java Arguments <a href="#java-arguments" id="java-arguments"></a>

These can help both server and client with performance in,

* Reducing Ram Usage. (*GC will clean up more efficiently*)
* Reduced Lag Spikes. (*GC will clean more frequently, reducing large lag spikes*)

#### Client Arguments <a href="#client-arguments" id="client-arguments"></a>

These can be set in your **Launcher**

<details>

<summary>Curseforge Launcher</summary>

If you’re using the Curseforge Launcher, open your **Settings**, choose **Minecraft** and scroll down to these Settings. [![](https://allthemods.github.io/alltheguides/help/img/CurseforgeJVM.png)](https://allthemods.github.io/alltheguides/help/img/CurseforgeJVM.png)

</details>

<details>

<summary>ATLauncher</summary>

Open your pack **Settings**, click **Java/Minecraft** and put your args into the big `Java Parameters` box. [![](https://allthemods.github.io/alltheguides/help/img/javaAT1.png)](https://allthemods.github.io/alltheguides/help/img/javaAT1.png) [![](https://allthemods.github.io/alltheguides/help/img/javaAT2.png)](https://allthemods.github.io/alltheguides/help/img/javaAT2.png)

</details>

Default Java 8-11 Client Arguments

```
-XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1NewSizePercent=30 -XX:G1MaxNewSizePercent=40 -XX:G1HeapRegionSize=32M -XX:G1ReservePercent=20 -XX:G1HeapWastePercent=5 -XX:G1MixedGCCountTarget=4 -XX:InitiatingHeapOccupancyPercent=15 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=5 -XX:SurvivorRatio=32 -XX:+PerfDisableSharedMem -XX:MaxTenuringThreshold=1 -Dusing.aikars.flags=https://mcflags.emc.gs -Daikars.new.flags=true
```

Default Java 17+ Client Arguments

```
-XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
```

Default Java 21 Client Arguments

```
-XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
```

Java 21 Client Arguments | If you have lots of ram (12GB+), try ZGC

```
-XX:+UseZGC -XX:+ZGenerational -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:+PerfDisableSharedMem -XX:+UseDynamicNumberOfGCThreads
```

***

#### Server Arguments <a href="#server-arguments" id="server-arguments"></a>

These are set in the `user_jvm_args.txt` file in your server folder

Java 17 Server Arguments

```
-Xms4G -Xmx6G -XX:+UseG1GC -XX:+ParallelRefProcEnabled -XX:MaxGCPauseMillis=200 -XX:+UnlockExperimentalVMOptions -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:G1NewSizePercent=30 -XX:G1MaxNewSizePercent=40 -XX:G1HeapRegionSize=8M -XX:G1ReservePercent=20 -XX:G1HeapWastePercent=5 -XX:G1MixedGCCountTarget=4 -XX:InitiatingHeapOccupancyPercent=15 -XX:G1MixedGCLiveThresholdPercent=90 -XX:G1RSetUpdatingPauseTimePercent=5 -XX:SurvivorRatio=32 -XX:+PerfDisableSharedMem -XX:MaxTenuringThreshold=1
```

Java 21 Server Arguments

```
-Xms4G -Xmx6G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
```

Java 21 Server Arguments | For fast CPUs with 4+ cores & lots of ram (8-12GB), try ZGC:

```
-Xms8G -Xmx12G -XX:+UseZGC -XX:+ZGenerational -XX:SoftMaxHeapSize=10g -XX:+DisableExplicitGC -XX:+AlwaysPreTouch -XX:+PerfDisableSharedMem -XX:+UseDynamicNumberOfGCThreads
```