Port Forwarder

Port Forwarder lets you redirect TCP and UDP network traffic from one port to another on your Android device. It works as a local relay that listens for incoming connections on a port you choose and forwards that traffic to a destination IP address and port on your network.

This port forwarding app is built for developers, network administrators, and anyone who needs to route traffic between devices on a local network. Common use cases include accessing a web server running on a computer from another device, testing services behind a different port, and redirecting traffic from one machine to another without changing the server configuration.

How port forwarding works in this app:

You create a forwarding rule by specifying a listen port on your phone, a destination IP address, and a destination port. When the rule is active, any traffic that arrives on the listen port gets forwarded to the destination. The app supports both TCP port forwarding for connection-based traffic and UDP port forwarding for connectionless protocols like DNS or game servers.

Key capabilities:

- Create multiple port forwarding rules and run them at the same time
- Choose between TCP and UDP protocols for each rule
- Set a custom listen address or use 0.0.0.0 to accept connections on all network interfaces
- Specify any destination IP address and port number on your local network
- Start and stop individual rules independently
- View live metrics including bytes received, bytes sent, active connections, and current throughput
- Monitor real-time data transfer speed with a visual throughput gauge
- Track peak transfer rates and total data transferred per rule
- Runs as a foreground service so port forwarding stays active when the app is in the background
- Persistent notification showing the number of active rules with a one-tap stop option
- Rules are saved locally and persist across app restarts

The app uses non-blocking I/O and the reactor pattern for handling TCP connections. This means it can manage many simultaneous connections without creating a separate thread for each one. For UDP forwarding, the app maintains a client mapping table with automatic cleanup of idle connections after 60 seconds.

Port forwarding is useful in several networking scenarios. If you are running a local development server on your laptop and want to reach it from a different port, you can set up a forwarding rule on your phone that acts as a bridge. If you need to test how a service responds when accessed through a different port number, a simple TCP or UDP forwarding rule handles that. Network administrators can use this tool to relay traffic between subnets when devices are connected through the phone.

The live dashboard gives you a clear view of what is happening with each active rule. You can see the exact amount of data flowing in each direction, the number of open connections, and the current transfer speed. This is helpful for verifying that your port forwarding setup is working correctly and for diagnosing network issues.

No account or sign-in required. No data is sent to any server. All port forwarding happens locally on your device and your network. The app requires only network permissions to function.

Port Forwarder supports Android 7.0 and above.