Could not connect to React Native development server on Android

Question

When I run react-native run-android, it gives me the following error:

Could not connect to development server

Answer 1

Default metro builder runs on port 8081. But in my PC, this port is already occupied by some other process (McAfee Antivirus) So I changed the default running port of metro builder to port number 8088 using the following command

react-native run-android start --port=8088

This resolved my issue and the app works fine now.

PS: You can check whether a port is occupied or not in windows using "Resource Monitor" app. (Under "Listening Ports" in "Network" tab). Check out this link for detailed explanation: https://www.paddingleft.com/2018/05/03/Find-process-listening-port-on-Windows/