Debugging Native Code

Projects with Native Code Only

The following section only applies to projects with native code exposed. If you are using the managed Expo workflow, see the guide on prebuild to use this API.

Accessing Logs

You can display the native logs for an iOS or Android app by using the following commands in a terminal while the app is running:

# For Android:
npx react-native log-android
# Or, for iOS:
npx react-native log-ios

You may also access these through Debug > Open System Log… in the iOS Simulator or by running adb logcat "*:S" ReactNative:V ReactNativeJS:V in a terminal while an Android app is running on a device or emulator.

💡 Custom Native Logs

If you are writing a Native Module and want to add custom logs to your module for debugging purposes, you can use the following method:

Android (Java/Kotlin)

In your native module, use the Log class to add logs that can be viewed in Logcat:

Java

import android.util.Log;