290
votes

I am trying to create a sample application with Flutter (fresh installation). Android Studio is also installed (fresh installation).

Here is the output of flutter run

flutter run
No connected devices.

The output of flutter doctor:

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, v0.1.5, on Linux, locale en_US.UTF-8)
[✓] Android toolchain - develop for Android devices (Android SDK 27.0.3)
[✓] Android Studio (version 3.0)
[!] VS Code (version 1.20.1)
[!] Connected devices
! No devices available

! Doctor found issues in 2 categories.

Is there a solution to this problem?

30
Do you have a device connected (USB debugging enabled) or an emulator running? - Günter Zöchbauer
do flutter devices to check if flutter can find any devices or not - denvercoder9
"No connected devices" error usually means that you don't have enabled on your device the developer options. - Shomu
For me this happens for about 1 minute then it seems to right itself. Android studio works fine immediately, but Flutter seems excessively slow at just about everything, including getting the emulator to be recognized. Maybe try some patience and come back after a cup of coffee? - Mitch
I had same problem, I've fixed by changing the USB Cable, because some cables are for power only. - Thiago Silva Ferreira

30 Answers

242
votes

Flutter supports both iOS and Android device/simulators.

In the terminal, run the flutter devices command to verify that Flutter recognizes your connected Android device.

Here is a reference document on how you can set up a device/simulator to run your application.

For, Android (on a Mac system)

Set up your Android device

To prepare to run and test your Flutter app on an Android device, you’ll need an Android device running Android 4.1 (API level 16) or higher.

  1. Enable Developer options and USB debugging on your device. Detailed instructions are available in the Android documentation.
  2. Using a USB cable, plug your phone into your computer. If prompted on your device, authorize your computer to access your device.
  3. In the terminal, run the flutter devices command to verify that Flutter recognizes your connected Android device.
  4. Start your app by running flutter run.

By default, Flutter uses the version of the Android SDK where your ADB tool is based. If you want Flutter to use a different installation of the Android SDK, you must set the ANDROID_HOME environment variable to that installation directory.

Set up the Android emulator

To prepare to run and test your Flutter app on the Android emulator, follow these steps:

  1. Enable VM acceleration on your machine.
  2. Launch Android Studio → menu ToolsAVD Manager and select Create Virtual Device.
  3. Choose a device definition and select Next.
  4. Select one or more system images for the Android versions you want to emulate, and select Next. An x86 or x86_64 image is recommended.
  5. Under Emulated Performance, select Hardware - GLES 2.0 to enable hardware acceleration.
  6. Verify the AVD configuration is correct, and select Finish.

For details on the above steps, see Managing AVDs.

  1. In Android Virtual Device Manager, click Run in the toolbar. The emulator starts up and displays the default canvas for your selected OS version and device.
  2. Start your app by running flutter run. The connected device name is Android SDK built for <platform>, where platform is the chip family, such as x86.

Open & Connect Device using Android Studio:

Here is an easier way to open and connect simulators/devices.

Android Studio shows a list of emulators/simulators (installed in your system) or devices (connected to your system). Just select a device you want to open from a list, and run the project.

Enter image description here

163
votes

Use:

flutter config --android-sdk ANDROID_SDK_PATH

Or

  • Device Not Found (when setting up Flutter in Android Studio)
  • Project structure -> select latest Android API in Project SDK

Enter image description here

57
votes

This was my solution:

My "Developer Options" was ON, but the "USB Debugging" was OFF.

So I turned ON the USB Debugging and the problem was solved.

41
votes

I solved the AVD problem with Flutter using the Flutter console.

Step 1:

C: \ Users \ valer> flutter emulators
6 available emulators:

3.2_QVGA_ADP2_API_22 _-_ Lollipop • 3.2in QVGA (ADP2) • Generic • 3.2 QVGA (ADP2) API 22 - Lollipop
Android_ARMv7a
Android_Accelerated_x86
Nexus S API Google Nexus S API 23
Nexus_S_API_25_1080x1920_Nougart_7.1.1_ • pixel • Google • Nexus S API 25 1080x1920 (Nougart 7.1.1)
Pixel_API_28 • pixel • Google • Pixel API 28

To run an emulator, run flutter emulators --launch <emulator id>.

Step 2:

C: \ Users \ valer> flutter emulators --launch Pixel_API_28
38
votes

None of the suggestions worked until I ran:

flutter config --android-sdk ANDROID_SDK_PATH

Use "PATH" = your path. For example:

flutter config --android-sdk C:\Users\%youruser%\AppData\Local\Android\Sdk
29
votes

In my case

Menu FileProject Structure

Select the latest SDK:

Enter image description here

21
votes

I encountered the same problem as you did. It turns out that your device is not connected with your computer.

Note:

  • If you are using Xcode, if both your computer and the device are using the same Wi-Fi AP, you don't have to connect the device with the computer.
  • For Android, or iOS running under terminal command, if you are using command line to run this, you have to make sure they are connected via cables. Sharing the same Wi-Fi AP does not work. Make sure your device is really connected.
  • Make sure you allowed USB Debugging on your Android device.

If this still does not work, try to fire the below command, where you can get richer information and details:

flutter run --verbose
18
votes

What I needed to do:

flutter emulators

It will list all available emulators. For iOS you will need to open the simulator first.

flutter emulators --launch EMULATOR NAME

This will launch the emulator.

And to build it:

flutter run -d "EMULATOR ID"
16
votes

I ran mine with Genymotion, probably the best for Flutter.

Setting up is less painful, but make sure setting ADB under:

Enter image description here

Your Andouird SDK path

Mine is C:\Users\user\AppData\Local\Android\Sdk.

14
votes

Sometimes you have everything perfect, but the device is no longer authorized on ADB. In such cases you have ADB, but it will not show you in connected devices.

Steps to fix this issue

1. Check if authorized: Open terminal/cmd/PowerShell and write adb devices. It will show you all connected devices to the PC.

<ANDROID_SDK_HOME>\platform-tools>adb devices
List of devices attached
4df798d76f98cf6d        unauthorized

2. Revoke USB debugging on the phone

If the device is shown as unauthorized, go to the developer options on the phone and click "Revoke USB debugging authorization" (tested with Android 4.1 (Jelly Bean) and Samsung Galaxy S III).

3. Restart ADB Server:

adb kill-server
adb start-server

4. Reconnect the Device and run following command again: adb devices

Now it should display authorized.

5. Ready to go.

Now, open your editor, Android Studio or Visual Studio Code, and check if your device is showing in connected devices or not.

You can simply check that with the flutter doctor command.

12
votes

For Windows users,

Set the environment variable PATH for the Flutter SDK (...\flutter_windows_v0.2.8-beta.zip\flutter\bin)

No device connect

For more information, you can check blog post Flutter - How to install Flutter in Android Studio

Here is the information from the mentioned page:

Add Flutter to the Windows environment variable PATH:

  1. Navigate in to the Flutter SDK folder.
  2. Go inside the bin folder and copy the directory path (in your case C:\Flutter\bin)
  3. Go to “Control Panel > User Accounts > User Accounts > Change my environment variables”
  4. Under “User variables”, select the PATH variable and click Edit.
  5. Put C:\Flutter\bin and apply.

Same as the Flutter environment, we have to set the Android SDK path if it is on custom location.

  1. Navigate into the Android SDK folder.
  2. Copy the directory path (in your case ..AndroidStudioSDK\sdk)
  3. Go to Control Panel* → User AccountsUser AccountsChange my environment variables
  4. Under “User variables” select the PATH variable and click Edit.
  5. Enter ..AndroidStudioSDK\sdk with ANDROID_HOME and apply.

Tips:

If you facing the following issue,

1.[✗] Android toolchain - develop for Android devices ✗ Unable to locate Android SDK. Install Android Studio from https://developer.android.com/studio/index.html On the first launch, it will assist you in installing the Android SDK components. (or visit https://flutter.io/setup/#android-setup for detailed instructions).

If Android SDK has been installed to a custom location, set $ANDROID_HOME to that location.

You can resolve it with the following command.

flutter config --android-sdk <android-sdk-location> OR flutter config --android-sdk "android-sdk-location"

  1. Error: Unknown argument --licenses

You can resolve it with the following command.

flutter -v doctor --android-licenses

Now, pick the emulator you want to use and click the green arrow to run the project. So, here default screen that is already designed.

10
votes

I am facing the same issue with Flutter. But I found another way to work, i.e.,

  1. First run Android Emulator

  2. Then go to your Flutter Console

  3. Run the command flutter doctor, anf check whether your emulator is showing under connected devices tag, e.g.,

    Enter image description here

  4. Now move to your Flutter project path via the Flutter console. E.g., for me it is D:\FlutterWorkspace\flutter_demo

  5. Then run the flutter run command. E.g.,

    Enter image description here

    Wait for few moments. You will see your app running in the Android Emulator.

    Enter image description here

10
votes

If you have

  • Downloaded the Flutter SDK
  • Connected your mobile device and enabled the developer option on the mobile and allowed USB debugging.

And if you are still getting "No device connected" then I think you should install the ADB driver.

It worked for me!!

Click here to download

9
votes

There should be at least one device/simulator connected to run Flutter applications.

Also make sure the USB debugging is enabled in developer settings.

8
votes

One option that I haven't see mentioned so far is that (for my setup) the Developer Option 'Select USB Configuration' must be set to MTP (Media Transfer Protocol).

7
votes

I am using Linux and here are the steps that can help. First open Android Studio with root permissions, (Windows: Right-click the program icon → Choose Run As Administrator, Linux: sudo ./studio.sh in the terminal)

Create emulator with Hardware - GLES 2.0 in hardware acceleration as mentioned here. Open a terminal in Android Studio (Alt + F12).

Run command flutter devices and see the list devices:

root@abc-OptiPlex-3050:~/flutter_workspace/my_app/my_app# flutter devices
   Woah! You appear to be trying to run flutter as root.
   We strongly recommend running the flutter tool without superuser privileges.

1 connected device:

Android SDK built for x86 • emulator-5554 • android-x86 •
Android 8.1.0 (API 27)(emulator)

Finally run flutter run from the terminal:

root@abc-OptiPlex-3050:~/flutter_workspace/my_app/my_app# flutter run
   Woah! You appear to be trying to run flutter as root.
   We strongly recommend running the flutter tool without superuser privileges.


Using hardware rendering with device Android SDK built for x86.
If you get graphics artifacts, consider enabling software rendering
with "--enable-software-rendering".
Launching lib/main.dart on Android SDK built for x86 in debug mode...
Initializing gradle...                                       0.7s
Resolving dependencies...                                    1.2s
Running 'gradlew assembleDebug'...                           1.5s
Built build/app/outputs/apk/debug/app-debug.apk.
I/FlutterActivityDelegate(25096): onResume setting current activity to this
Syncing files to device Android SDK built for x86...
D/        (25096): HostConnection::get() New Host Connection established
0xe8487780, tid 25116
D/EGL_emulation(25096): eglMakeCurrent: 0xe5b3d8a0: ver 2 0 (tinfo 0xe84832f0)

🔥  To hot reload changes while running, press "r". To hot restart (and
rebuild state),press "R".An Observatory debugger and profiler on
Android SDK built for x86 is available at: http://127.0.0.1:8100/
For a more detailed help message, press "h". To quit, press "q".

And do check the flutter-sdk path in your project.Configure file from this answer.

6
votes

The actual answer did not work for me.

But setting ANDROID_HOME in your ~/.bash_profile file, logging out, and then logging in, makes it work!

This may be an Android Studio issue since it is not setting this environment variable for the open projects.

5
votes

I had the same problems while I was debugging with a local Flutter engine. In such case, if you have set environment variable FLUTTER_ENGINE, you should unset it and restart you IDE.

5
votes

Follow these step:

Menu File -> Project Structure -> Project SDK(Select the SDK Path in the Android SDK) -> OK

Make sure your device is connected to the PC.

Open Git Bash and type:

flutter devices

Then run your Flutter app. It will work.

5
votes

Step 1: To check the connected devices, run: flutter devices

Step 2: If there aren't any connected devices to see in the list of available emulators, run: flutter emulators

Step 3: To run an emulator, run: flutter emulators --launch <emulator id>

Step 4: If there is no available emulator, run: flutter emulators --create [--name xyz]

==> For Android:

Step 1: To check the list of emulators, run: emulator -list-avds

Step 2: Now to launch the emulator, run: emulator -avd avd_name

==> For iOS:

Step 1: open -a simulator

Step 2: flutter run (in your app directory)

4
votes

Flutter needs a device to run the app. There are two choices for this.

  1. Run the app on your real phone.
  2. Run the app on a virtual device in your computer.

I would recommend Option 1 because it doesn't use your device resources and is faster.

Option 1:

Unlock developer options on your phone, go to developer setting and turn on USB debugging and connect your phone to your computer. Now run flutter run and it will work.

Option 2:

Open Android Studio, go to AVD Manager, add a virtual device if you haven't done that yet and run the virtual device. Now run flutter run again and it should work.

Note that this way works with any virtual device and not just virtual device from Android Studio.

4
votes

I solved the problem after changing "ANDROID_HOME" to the Environment variables and setting it to the location of your Android SDK...in my case C:\Android\Sdk.

4
votes

None of the above solutions worked for me, but I was able to solve it by invalidating catch and restarting my Android Studio:

Menu FileInvalidate Catches / Restart...

EDIT:::

To clear Android Studio’s cache and bring it out of its state of confusion

select ‘File > Invalidate Caches / Restart’ and then click the ‘Invalidate and Restart’ button.

Clean and rebuild your project.

3
votes

NOTE: I am using a Mi (Xiaomi) mobile (Redmi K20 Pro) which is running on Android 10

You need to do two things to show your device listing.

  1. Go to your Android Studio, menuFileProject Structure and choose the project SDK from the options. I chose the latest one from the menu.

  2. When you connect your real device to your PC/laptop, make sure you choose Transfer photos (PTP) mode.

NOTE: Don't choose File transfer mode. It will not work.

After doing the above two things, you can check the status of your device availability by writing flutter devices on the command prompt.

I hope it shows your mobile device.

3
votes

I had the same issue. Setting up the Android SDK is also a correct answer. But this is very simple -

  1. Import an Android project to a new Android Studio window.
  2. Close your current Flutter project Android Studio window.
  3. Import that Flutter project to a new Android Studio window.
2
votes

It basically needs a device "connected" to your development machine. If you're using a simulator/emulator running on the machine it should automatically be recognised as a connected device. Another way is to connect a physical device and the setup process varies slightly for Android and iOS devices.

2
votes

For Windows users,

The solution for me was running Android Studio as administrator

2
votes

For me it was

  1. adding "ANDROID_HOME" to the Environment variables and setting it to D:\dev\android\ (for me)

  2. adding "D:\dev\android\platform-tools" (for me) to environment variable PATH. I put flutter there before

  3. OK, OK, OK. Restart Android Studio

2
votes

In my case, flutter devices showed my device correctly and flutter run worked as expected. But the device is not shown in Android Studio.

Here is my solution:

In my .bash_profile, the Android SDK is configured like this:

export ANDROID_SDK_ROOT="~/Library/Android/sdk"

It seems the Flutter plugin can not recognise the ~, so I changed it to this way:

export ANDROID_SDK_ROOT="/Users/charliema/Library/Android/sdk"

Reopen Android Studio. It worked.

2
votes

You could try

flutter emulators

to show a list of already-created emulators.

Today, this shows me the two emulators in the list below.

Nexus_6_API_27 • Nexus 6 API 27 • Google • android

Pixel_2_API_27 • Pixel 2 API 27 • Google • android

You can then use something like

flutter emulators --launch Nexus_6_API_2 to start the emulator of choice

You can then use flutter run to test your app.

I use Visual Studio Code and tend to do use this approach which saves me having to load Android Studio to launch an emulator.