port 8081 already in use when "react-native run-ios"

Question

Yes i have read this but still don't know how to make it work. react native - Port 8081 already in use, packager is either not running or not running correctly Command /bin/sh failed with exit code 2

Originally i was doing this

1. react-native init Hello
2. react-native run-ios

Then hit this "port 8081 already in use".

Did read the react doc, https://facebook.github.io/react-native/docs/troubleshooting.html

1. cannot kill the process using 8081, it keeps on coming back,
   and i don't want to kill it
2. react-native start --port=8088
3. update node_modules/react-
native/React/React.xcodeproj/project.pbxproj file. Did it.

Where and which step should i run "react-native start --port=8088" ?

btw, i'm an average engineer, but if i cannot run the very 1st react-native sample in 2 hours, i just cannot see how it can fly, this is very annoying.

score 9 · Answer 1 · answered Jun 01 '18 at 19:30

9

In RN 0.55 you can fix this with:

react-native start --port=1234

and then in a different window:

react-native run-ios --port 1234

Versions:

✗ react-native --version
react-native-cli: 2.0.1
react-native: 0.55.4

answered Jun 01 '18 at 19:30

jcollum

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2

Actually `react-native start --port=1234` is not needed. `react-native run-ios --port 1234` is enough. – Bagusflyer Dec 18 '18 at 07:45

score 2 · Answer 2 · answered Aug 09 '22 at 23:53

Runing React Native Apps on Mac OS when port 8081 is already in use due to another service or APP

For ios emulator

Open Xcode and navigate to Pods -> Development Pods -> React-Core -> Default -> Base -> RCTDefines
Change #define RCT_METRO_PORT 8081 => #define RCT_METRO_PORT 8088 or to desired port number (make sure to change all ocurrencies on that file)
Run npx react-native run-ios --port 8088 (or desired port number and needs to match with the one on RCTDefines file) from the project folder

For Android

Just Runs npx react-native run-android --port=8088 (or desired port #) from the project folder

score 1 · Answer 3 · answered Apr 08 '20 at 08:54

In yarn managed project in package.json

 "scripts": {
      ...
    "ios": "npx react-native run-ios --port 19001 && npx react-native start --port 19001",
    "android": "npx react-native run-android --port 19001 && npx react-native start --port 19001",
    }

port 8081 already in use when "react-native run-ios"

3 Answers3

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