Dev’s favorite Port 5000 in use — macOS Monterey?

The Problem

After 3000, a very common port for web development is 5000 as a lot of web devs use this port for backend / frontend development. If you’ve just upgraded your mac to Monterey and don’t know why your backend at 5000 failed to start suddenly, then here it is —

Don’t worry, your code is good! Its the macOS who is responsible for this.

This is apparently due to the new AirPlay functionality. Control Center is listening to those ports for their “AirPlay Receiver”. And the good news is that you can turn off that.

The Solution

Solution is very easy. Just go to sharing settings and turn off the AirPlay Receiver.

But no idea why such a common web development port is used for such thing. Hope this helps!