Android development over USB

Expo’s default connection uses the local network. If the phone is on mobile data, has Wi-Fi disabled, or cannot reach the Mac, Expo Go can fail before JavaScript loads with Failed to download remote update.

With USB debugging enabled and the device connected:

adb devices
adb reverse tcp:8081 tcp:8081
npx expo start --localhost --android

Recreate the reverse mapping after reconnecting the USB cable or device. If the phone and Mac are on the same Wi-Fi network, npm run android is sufficient.

Treat a remote-update download failure as device-to-Metro connectivity first. API failures logged after the JavaScript bundle loads are separate application-level issues.