Port Mapper helps you publish a service running on your Mac so it can be reached through your router from another device or network. This is commonly used for game servers, development servers, remote tools, or other apps that need an incoming network connection.
Before you begin
- Make sure your Mac is connected to the network where you want to create the port mapping.
- Make sure the app, game, or server you want to expose is already running on your Mac.
- Check the documentation for that app or game to confirm the correct port number and protocol.
- Your router must allow automatic port mappings. Some routers disable this feature by default.
Allow local network access
The first time you use Port Mapper, macOS may ask whether the app can access devices on your local network. Choose Allow. Port Mapper needs this permission to find your router and publish your rules.
If you choose Don't Allow, Port Mapper may not be able to create mappings. You can change this later in macOS System Settings.
Main window overview
The main window shows your port mapping rules and their current status.
- Rule: The name you gave the mapping.
- Status: Whether the mapping is pending, mapped, unmapped, or disabled.
- Internal: The port used by the service on your Mac.
- External: The port exposed through your router.
- Protocol: TCP, UDP, or both.
- Enabled: Whether Port Mapper should publish this rule.
Create your first rule
- Open Port Mapper.
- Click New Rule. If you do not have any rules yet, click Create Rule.
- Enter a name, such as the name of the app, game, or server.
- Enter the internal port used by the service on your Mac.
- Enter the external port you want your router to expose.
- Select TCP, UDP, or both.
- Click Save.
After saving, Port Mapper will publish the rule automatically. The status will update in the main window.