How do I set or change the server port? — Minecraft

Q: My server won't start after changing the port — why?

Almost always because the port in server.properties doesn't match an allocation you own. Set it back to an allocated port and restart.

Every Minecraft server on Humble has an assigned port, shown as IP:port in the Console. If you want to run your server on a different port, you can — but the port has to be one that's actually allocated to your server, not just any number you pick.

How ports work here

Your server binds to a port that belongs to it. In the panel you can see your current address as IP:port right in the Console. If you want to use a second (or different) port, you first add it as an allocation in the Ports tab, and only then point your server at it. Extra ports are free to add.

Warning: Don't just type any number into server-port. It must be a port that's been allocated to your server in the Ports tab, or the server won't bind and won't start.

Step-by-step

Open your server and go to the Ports tab.
Add the port allocation you want to use (extra ports are free).
Go to the Files tab and open server.properties.
Set server-port= to match the allocated port exactly.
Save the file.
Restart the server for the change to take effect.

Tip: After restarting, check the Console — your new IP:port should reflect the port you set. Share that full address with players so they can connect.

Frequently asked questions

Can I use any port number I like? No. It has to be one allocated to your server in the Ports tab first. Otherwise the server can't bind to it.

Do extra ports cost anything? No, adding extra port allocations is free. You'll often need one for things like a Bedrock/Geyser UDP port.

My server won't start after changing the port — why? Almost always because the port in server.properties doesn't match an allocation you own. Set it back to an allocated port and restart.