How to run your own server jar on your Minecraft server

Choose Custom Jar in Edit Server Type (it is in the Your own jar group), upload your jar in Files, then type its exact file name in Settings, Game Settings, Server Jar File. Nothing is installed or managed for you: the server runs your jar as it is, and does not start until the name matches a file that is there.

When to use it

For a fork, a test build or a server program that is not in the panel's list of types. If the software you want is in the list (Paper, Purpur, Fabric, Forge and the others), use that type instead: the panel then installs it, finds the right Java and offers plugins or mods for it. See Minecraft server types explained.

Switch to Custom Jar

1. Back up your world if you want to keep it: How to back up, restore and reset your Minecraft world.
2. On the Overview page, click Edit Server Type.
3. In the Your own jar group (Upload a jar and run it. Nothing here is managed for you.), choose Custom Jar and click Next step.
4. On the review step, choose whether to start clean or keep your files, tick the confirmation and click Change server type. See How to change your Minecraft version or server type.

Upload and name your jar

1. Open the Files tab and upload your jar into the main folder, the one that opens first. See How to upload, edit and manage your server files.
2. Open the Settings tab and click Game Settings.
3. In Server Jar File, type the jar's exact name, for example my-server.jar. Only letters, numbers, dots, dashes and underscores, ending in .jar.
4. Start the server and watch the Console.

Pick the Java version

Your jar may need a particular Java. Open Settings, Launch Details and choose it under Docker image: Java 26, 25, 21, 17, 11 or 8. See How to change the Java version of your Minecraft server.

Good to know

• The panel only counts the server as started when the Console shows Minecraft's ready line, which ends For help, type "help". A jar that prints something else may look as if it is still starting.
• Memory and the panel's Java flags are set for you, as on every type. You can add your own flags under Startup Parameters: How to add Java startup flags to your Minecraft server.
• A Custom Jar server has no Players page and no invite links. Use the Console for the whitelist and bans.
• If your jar stops and asks you to accept the EULA, see Your Minecraft server stops because the EULA is not accepted.