React native Cannot connect to react-devtools using android simulator

Troubleshooting React Native Devtools Connection Issues on Android Simulator

Connecting your React Native app to React Devtools provides a powerful debugging experience. However, getting the connection working on an Android simulator can sometimes be tricky. This article guides you through common issues and solutions to establish a successful connection.

1. Verify Devtools is Running

• Ensure you have the Chrome browser open.
• Navigate to chrome://inspect/#devices.
• Check if React Devtools is running. If it’s not, launch it by clicking the “Open Devtools” button.

2. Verify Emulator Connection

• Ensure your Android emulator is running and the app is loaded.
• Confirm that the emulator is connected to your computer’s network.

3. Check Development Mode

• Ensure the app is running in development mode by setting the dev option to true in your index.js or App.js file:

  import { AppRegistry } from 'react-native';
  import App from './App';
  
  AppRegistry.registerComponent('yourAppName', () => App);
  
  AppRegistry.runApplication('yourAppName', {
    rootTag: document.getElementById('root'),
    initialProps: {},
    dev: true,
  });
  

4. Check Debugging Ports

• Verify that the debugging port (8081 by default) is not blocked by firewalls or other applications. You can check your firewall settings.

5. Consider Debugging Bridges

• If the connection still fails, try installing and using the react-native-debugger package. It provides a dedicated bridge for improved debugging:

npm install react-native-debugger --save

• After installation, start the react-native-debugger server by running the following command:

react-native-debugger

• Access the debugger by opening the URL in your browser, typically http://localhost:9090/. You can then connect your app to this debugger.

6. Emulator Configuration

• Make sure that the Android emulator is configured for debugging:
  • Go to the “Settings” of your emulator.
  • Choose “Developer options.”
  • Enable “USB debugging.”

7. Common Errors and Solutions

8. Troubleshooting Network Configuration

• Check your network configuration for any issues that might be preventing communication between the emulator and your computer.

9. Restarting Services

• Restart your emulator, development server (npm start), and the Chrome browser. Sometimes, a simple restart can resolve temporary connectivity problems.

10. Additional Tips

• Ensure your Android emulator is running on the latest stable version.
• Try updating your React Native and related dependencies.
• If you are working with a VPN, try disabling it to see if it resolves the issue.