Custom JAR Servers are Here

ARM-MC's biggest update yet has arrived. You can now run any Java-based Minecraft server software directly from your Android device, including Paper, Spigot, Bukkit, Fabric, and Vanilla. Bring your mods, your plugins, and your existing worlds.

What's New

This major release introduces Custom JAR support as a first-class option alongside PumpkinMC. Here's everything that's included:

• Custom JAR servers: Vanilla, Spigot, Bukkit, Fabric, and Paper
• Mod & plugin support: upload via the in-app file browser
• File editor: edit .json, .yml, .properties, and .txt files directly in the app
• Syntax highlighting: color-coded file previews for config files
• Extended file actions: rename, clear folder, and unzip
• Custom world import: upload a .zip of your world via the file browser
• Memory slider: fine-tune how much RAM is allocated to your JAR server
• Various stability and textual improvements

PumpkinMC vs Custom JAR: Which Should You Use?

ARM-MC gives you two server software options. Here's how they compare:

Step 1: Install ARM-MC

Download ARM-MC from the Google Play Store. Make sure your device is arm64-v8a (most Android phones from 2018 onwards are).

Once installed, you can optionally create an account. Registering gives you access to our free tunneling service, which provides a public address like elite-golem-20.arm-mc.com so your friends can join without any port-forwarding.

Step 2: Obtain a JAR File

Due to Google Play restrictions, ARM-MC cannot download server JARs automatically. You'll need to download the .jar file from the server software's own website and transfer it to your device. Here are the official download pages for the most popular options:

• Paper: papermc.io (recommended for plugins)
• Fabric: fabricmc.net (recommended for mods)
• Spigot: spigotmc.org
• Vanilla: minecraft.net/en-us/download/server

Step 3: Create and Configure Your Server

Tap the + button on the server page to create a new server. In the software dropdown, select Custom JAR. You'll then be prompted to upload your .jar file from your device's storage.

With your JAR selected, you can configure the remaining server settings:

• Server name & description
• Gamemode & difficulty
• Memory slider: allocate RAM to your server. Most JAR servers need at least 2GB to start, and 4 to 6GB for comfortable play with players online.
• View distance & simulation distance: lower these values if you experience in-game freezes. They have the biggest impact on RAM and CPU usage.
• Max players: more players means more load on your device.

Step 4: Start Your Server

Once configured, press the Start button on the server card. The server will start within a few seconds (JAR servers take longer than PumpkinMC). Navigate to the Console tab to view logs and send commands like op or whitelist add.

To find your server's address, check the top right of your active server card. If you registered an account and are using the tunneling service, it will look like elite-golem-20.arm-mc.com. For local hosting it will be something like 192.168.1.1:25565.

Step 5: Adding Plugins & Mods

Open your server's files by pressing the file button on the server card, or navigating to the Files page and opening your server's folder.

Adding a Plugin (Paper / Spigot)

1. Navigate to the plugins folder inside your server's root directory.
2. Press the + button at the bottom to upload a .jar plugin file.
3. Restart your server for the plugin to load.

Adding a Mod (Fabric)

1. Navigate to the mods folder inside your server's root directory.
2. Press the + button at the bottom to upload a .jar mod file.
3. Restart your server for the mod to load.

Step 6: Importing a Custom World

You can replace the default world with your own by importing a .zip archive of your world folder:

1. Open your server in the file browser and find the world folder.
2. Press the three-dot menu on the world folder and select Clear Folder to remove the existing world data.
3. Open the now-empty world folder and press the + button to upload your .zip file.
4. Once uploaded, press the three-dot menu on the zip file and select Unzip. The world files will unpack directly into the folder and the zip archive will be deleted.
5. Start your server. Your imported world will load automatically.

Performance Tips

JAR servers are significantly more resource-intensive than PumpkinMC. Here are some settings that have the biggest impact on performance:

• View distance: reduce to 6 to 8 for better performance (default is often 10+)
• Simulation distance: keep this at 4 to 6 on mobile
• Max players: every connected player increases RAM and CPU usage
• Memory allocation: allocate as much as your device can spare, but leave at least 1 to 2GB for Android itself

This feature is not recommended for pre-2018 devices or devices with less than 6GB of total RAM. Flagship phones from the last few years will see the best results.

Join the Community

Have questions, running into issues, or want to share your setup? Join our Discord server. We also have a dedicated #getting-started channel with a step-by-step setup guide.