React native change listening port

Question

I am using react native android and having face issues to deploy the app on an android device. When I run

react-native start, it won\'t start dev server

Answer 1

Actually, in the current version of React Native, configs of metro bundler are in the @react-native-community/cli and for changing the default PORT of metro bundler we should change the default PORT just by export an environment variable by the following command inside the project path:

export RCT_METRO_PORT=8590

Then in the ios folder of your project find the Pods folder and inside the Pods folder seek RCTDefines.h files, there are two of them, inside both of them change the 8081 to 8590.

Surely, for a test we can run the echo $RCT_METRO_PORT and if you see the new PORT 8590, it is changed now and we can run our project with default commands like yarn start and then yarn ios or yarn android.

Hint: for connecting to the React Native Debugger press ⌘+t and change the 8081 port to 9095.

Answer 2

When you excute command like

./node_modules/react-native/scripts/launchPackager.command

to start a debug server,append args like

---port 8082

it works for me in React native 0.53.3.

Answer 3

Set RCT_METRO_PORT, example:

export RCT_METRO_PORT=8765

Answer 4

You can use this react-native-port-patcher which replaces the default 8081 port with your desired port number.

Answer 5

Not sure if this is documented or not[1], you can specify the port via a CLI argument, like this:

react-native start --port 9988

I found it in the source code, and it worked on my local machine :)

https://github.com/facebook/react-native/blob/master/local-cli/server/server.js#L30

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[1] This is now documented here: https://facebook.github.io/react-native/docs/troubleshooting#using-a-port-other-than-8081

Answer 6

The simplest solution is:

The below command will build Android or iOS package which will listen to port 1234

For iOS: react-native run-ios --port=1234

For Android react-native run-android --port=1234

If you are using metro-server then you can add port under server object like :

server:{ port:1234 }

or

run

react-native start --port=1234

Find out more configuration for metro-server here: https://facebook.github.io/metro/docs/en/configuration

But requires 0.55 and above.