Home » Android » android – adb -s ….. error: more than one device/emulator

android – adb -s ….. error: more than one device/emulator

Posted by: admin May 14, 2020 Leave a comment


I am working with react native, and would like to switch adb to wifi for easier debugging.

I connect my device using usb, then type these commands.

adb tcpip 5555

Then I disconnect my usb cable and enter this command

adb connect
connected to

adb devices result in the following

adb devices
List of devices attached        device

So it only shows one device connected.
However trying this command

adb reverse tcp:8081 tcp:8081

gives me the following error even though only one device is shown with adb devices command as shown above

error: more than one device/emulator

So I tried this command but I also get the same error

adb -s reverse tcp:8081 tcp:8081
error: more than one device/emulator

Trying the following gives me the same error

adb -s "" reverse tcp:8081 tcp:8081
adb -s "" reverse tcp:8081 tcp:8081
adb -s reverse tcp:8081 tcp:8081

even trying to use the device id which I copied when it was connected to usb resulted in the same error

adb -s deviceid reverse tcp:8081 tcp:8081

Is there a way to make adb reverse work when adb is connected wireless?

Thanks for advance.

How to&Answers:

When I am facing the same issues than doing like below:

1) kill your process of 8081 port for using this command : kill -9 $(lsof -t -i:8081)

2) Reset your adb connection with : adb usb if you want to run via wifi then connect your device again : adb tcpip 5555

3) Start your npm : npm start

4) Then after you can run your react native app : react-native run-android

and it’s works fine for me.


Start task manager
and kill adb.exe process
and run
adb devices


I made two changes to the steps to get this working.

1) BEFORE disconnecting the wire from my phone, I ran adb reverse tcp:8081 tcp:5555 (note the 5555 port number for the phone) and adb connectMY.PHONE.IP.ADDRESS:5555` (with port number).

Only now did I disconnect the wire.

Then I installed the app, although it probably would work if the app was already installed.

2) After the app was installed and I was getting errors “Unable to load Script” and “Could not connect to development server”,

  • opened the developer menu (shake the phone with the React Native app open) and selected “Dev Settings”. Selected “Debug server host & port for device” from the menu.
  • In the window on my phone I entered MY.COMPUTER.IP.ADDRESS:8081

Now I could open/close the app for a reload, and shake -> debug JS remotely.