MacOS EADDRINUSE: Fixing Port Already in Use Errors

The EADDRINUSE error on MacOS indicates that an application is attempting to bind to a network port already in use by another process.

This is a frequent issue when running multiple instances of web servers, development environments, or testing scripts.

To resolve this, first identify the process occupying the port using the command lsof -i :PORT (replace PORT with the actual port number).

The output will show the process ID (PID) of the culprit.

You can terminate it using kill -9 PID or gracefully stop the application.

If you require multiple applications on the same port, explore proxy solutions like nginx or configure different ports for each application in their respective settings.

Developers can leverage Node.js tools like kill-port to automate this process.

Additionally, consider reviewing your application code to ensure proper port handling and avoid lingering processes by closing connections gracefully.

Regularly reviewing active ports and streamlining your development environment can prevent recurrence of EADDRINUSE errors.