When working with Dart or Flutter projects in Android Studio, one of the most common issues developers encounter is the “No Devices Found” error. This error prevents you from running your app on either a physical device or an emulator. Fortunately, the problem can usually be solved with the right configurations and troubleshooting steps. This guide provides a detailed explanation of the causes and practical solutions for fixing this issue.
Understanding the Error
The No Devices Found error appears when Android Studio cannot detect an emulator or physical Android device. It can happen in various situations, including:
- Emulator not properly configured in Android Studio.
- Physical device not connected via USB or missing drivers.
- Dart and Flutter SDK not correctly installed.
- Environment variables not set up.
- ADB (Android Debug Bridge) not running or outdated.
Step-by-Step Solutions
1. Check Flutter and Dart Installation
Before running your project, ensure Flutter and Dart SDKs are installed and available in your system path. Open your terminal and type:
flutter doctor
The command will display the status of your Flutter, Dart, and Android Studio setup. If you see warnings or errors (e.g., missing Android SDK), follow the suggested fixes.
2. Configure Android Emulator
If you are using an emulator, make sure it is correctly set up:
- Open Android Studio.
- Go to Tools > Device Manager.
- Create a new virtual device if none exists.
- Start the emulator before running your Dart project.
You should now see the emulator listed when running the following command:
flutter devices
3. Enable Developer Options on Physical Device
If you plan to use a real Android device:
- Enable Developer Options on your phone (tap “Build Number” 7 times in Settings).
- Enable USB Debugging in Developer Options.
- Connect your device to your computer using a USB cable.
- Accept the “Allow USB Debugging” prompt on your device.
Then check if the device is detected by running:
adb devices
You should see your device listed. If not, you may need to install the proper USB drivers (especially on Windows).
4. Restart ADB Server
Sometimes, ADB becomes unresponsive. Restarting the ADB server often fixes the problem:
adb kill-server adb start-server
Now re-run:
flutter devices
5. Update Environment Variables
Make sure the Android SDK and platform-tools paths are added to your system environment variables.
For example, on macOS/Linux add this to ~/.bashrc
or ~/.zshrc
:
export ANDROID_HOME=$HOME/Library/Android/sdk export PATH=$PATH:$ANDROID_HOME/emulator export PATH=$PATH:$ANDROID_HOME/tools export PATH=$PATH:$ANDROID_HOME/platform-tools
On Windows, add the SDK paths to your system Environment Variables under Path.
6. Configure Dart in Android Studio
Sometimes, Dart plugin issues can prevent devices from showing up. Verify that:
- Dart and Flutter plugins are installed (File > Settings > Plugins).
- Project SDK is set to Flutter (File > Project Structure).
- Dart SDK path is correctly configured.
Example: Running a Dart App on Emulator
Let’s test a simple Dart-based Flutter application to confirm the device setup works.
import 'package:flutter/material.dart'; void main() { runApp(const MyApp()); } class MyApp extends StatelessWidget { const MyApp({super.key}); @override Widget build(BuildContext context) { return MaterialApp( home: Scaffold( appBar: AppBar(title: const Text('Device Test App')), body: const Center(child: Text('Hello, Android Studio with Dart!')), ), ); } }
Run the app by selecting your emulator or connected device in Android Studio, or using:
flutter run
Troubleshooting Tips
Problem | Possible Cause | Solution |
---|---|---|
Device not detected | USB debugging disabled | Enable USB debugging in Developer Options |
Emulator not showing | Emulator not started | Start emulator in Device Manager before running |
ADB not responding | ADB crashed or outdated | Restart ADB using adb kill-server |
Flutter doctor errors | SDK not installed or missing PATH | Install SDK and set environment variables |
Conclusion
The No Devices Found error in Android Studio when using Dart or Flutter is frustrating but solvable. By checking your SDK installation, configuring emulators, enabling USB debugging, and ensuring ADB is running, you can quickly resolve the issue and get back to coding. If problems persist, consider reinstalling the Android SDK or updating Android Studio to the latest version.
For additional guidance, you can check the official Flutter documentation here: Flutter Installation Guide.