# Run a custom server jar

> Run a server jar we do not list: upload it, turn on Custom JAR in the settings and pick the Java version it needs.

Source: https://fadehost.com/docs/custom-jar/

The catalogue covers vanilla, Paper, Purpur, Spigot, Fabric, Forge, NeoForge, Mohist and the proxies. For anything else (a fork, a beta build, a private jar), run your own.

## Set it up

1. **Files**: upload the jar into the server folder.
2. **Settings**, **General**, **Custom JAR**: turn it on and enter the jar's file name. Pick the **Java version** the jar needs; the default follows the Minecraft version, and a jar built for a newer Java will say so in the console.
3. Restart.

The memory flags are still set from the server's RAM setting, so there is no start script to write.

## When to use it

- A fork such as Leaf, Pufferfish or Folia that we do not list.
- A specific build of Paper or Fabric for a plugin that has not caught up.
- A modded server assembled by hand from a server pack whose loader jar you want to keep exactly as shipped.

## Good to know

- A custom jar is not updated for you. Turn Custom JAR off to return to the managed jar and version switching.
- Keep the file name stable: renaming the jar means updating the setting.
- Jars that need Java 8 (1.12.2 and older) work; the Java version field goes down to 8.