Desktop support for Flutter

Contents

Desktop support allows you to compile Flutter source code to a native Windows, macOS, or Linux desktop app. Flutter’s desktop support also extends to plugins—you can install existing plugins that support the Windows, macOS, or Linux platforms, or you can create your own.

Beta Snapshot in stable channel

To make it easier to try out desktop support for Flutter, we are shipping a snapshot of Flutter’s desktop beta on the stable channel. This means that you can easily try desktop support without needing to switch to the Flutter beta channel. However, the snapshot included in the stable channel won’t be updated until the next Flutter stable release. If you want the latest version of desktop support, you must switch to the Flutter beta channel.

Requirements

To create a Flutter application with desktop support, you need the following software:

Additional Windows requirements

For Windows desktop development, you need the following in addition to the Flutter SDK:

  • Visual Studio 2019 (not to be confused with Visual Studio Code). For Win32 you need the “Desktop development with C++” workload installed, including all of its default components. For UWP you need the “Universal Windows Platform development” workload installed, with the optional UWP C++ tools.

Additional macOS requirements

For macOS desktop development, you need the following in addition to the Flutter SDK:

Additional Linux requirements

For Linux desktop development, you need the following in addition to the Flutter SDK:

The easiest way to install the Flutter SDK along with these dependencies is by using snapd. For more information, see Installing snapd.

Once you have snapd, you can install Flutter using the Snap Store, or at the command line:

$ sudo snap install flutter --classic

If snapd is unavailable on the Linux distro you’re using, you might use the following command:

$ sudo apt-get install clang cmake ninja-build pkg-config libgtk-3-dev

Create a new project

You can use the following steps to create a new project with desktop support.

Set up

At the command line, perform the following commands to make sure that you have the latest desktop support and that it’s enabled. If you see “flutter: command not found”, then make sure that you have installed the Flutter SDK and that it’s in your path.

$ flutter config --enable-<platform>-desktop

Where <platform> is windows, macos, or linux:

$ flutter config --enable-windows-desktop
$ flutter config --enable-macos-desktop
$ flutter config --enable-linux-desktop

For Windows UWP desktop support perform the following commands to switch to the dev channel, upgrade Flutter, and enable UWP.

$ flutter channel dev
$ flutter upgrade
$ flutter config --enable-windows-uwp-desktop

To ensure that desktop is enabled, list the devices available. You should see something like the following (you’ll see Windows, macOS, or Linux, depending on which platform you are running on):

$ flutter devices
1 connected device:

Windows (desktop) • windows • windows-x64 • Microsoft Windows [Version 10.0.18362.1082]
macOS (desktop)   • macos   • darwin-x64  • macOS 11.2 20D64 darwin-x64
Linux (desktop)   • linux   • linux-x64   • Linux

You might also run flutter doctor to see if there are any unresolved issues. It should look something like the following on Windows:

PS C:\> flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel stable, 2.0.6, on Microsoft Windows [Version 10.0.19042.804], locale en-AU)
[√] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
[√] Chrome - develop for the web
[√] Visual Studio - develop for Windows (Visual Studio Community 2019 16.9.5)
[√] Android Studio (version 4.1.0)
[√] VS Code (version 1.56.2)
[√] Connected device (3 available)

! No issues found!

On macOS, you might see something like the following:

$ flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 2.0.6, on macOS 11.3.1 20E241 darwin-x64, locale en)
[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.0)
[✓] Xcode - develop for iOS and macOS
[✓] Chrome - develop for the web
[✓] Android Studio (version 4.0)
[✓] VS Code (version 1.56.2)
[✓] Connected device (3 available)

• No issues found!

On Linux, you might see something like the following:

$ flutter doctor 
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel beta, 1.27.0-1.0.pre, on Linux, locale en_AU.UTF-8)
[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.3)
[✓] Chrome - develop for the web
[✓] Linux toolchain - develop for Linux desktop
[✓] Android Studio
[✓] Connected device (2 available)

If flutter doctor finds problems for a platform that you don’t want to develop for, you can ignore those warnings. You don’t have to install Android Studio and the Android SDK, for example, if you’re writing a Linux desktop app.

After enabling desktop support, restart your IDE. You should now see windows (desktop), macOS (desktop), or linux (desktop) in the device pulldown.

Create and run

Creating a new project with desktop support is no different than creating a new Flutter project for other platforms.

Once you’ve configured your environment for desktop support, you can create and run a desktop application either in the IDE or from the command line.

Using an IDE

After you’ve configured your environment to support desktop, make sure you restart the IDE if it was already running.

Create a new application in your IDE and it automatically creates iOS, Android, web, and desktop versions of your app. From the device pulldown, select windows (desktop), macOS (desktop), or linux (desktop) and run your application to see it launch on the desktop.

From the command line

To create a new application that includes desktop support (in addition to mobile and web support), run the following commands, substituting myapp with the name of your project:

$ flutter create myapp
$ cd myapp

To launch your application from the command line, enter one of the following commands from the top of the package:

PS C:\> flutter run -d windows
$ flutter run -d macos
$ flutter run -d linux

Windows UWP

To get started with Windows UWP you need to be using Windows 10. You need to install Visual Studio (not Visual Studio Code) with the “Universal Windows Platform development” workload and the optional Windows UWP C++ tools.

To configure Flutter for Windows UWP development, perform the following commands to switch to the dev channel, upgrade Flutter, and enable Windows UWP desktop support.

PS C:\> flutter channel dev
PS C:\> flutter upgrade
PS C:\> flutter config --enable-windows-uwp-desktop

To create a new application, run the following commands:

PS C:\> flutter create myapp
PS C:\> cd myapp

Running Flutter with Windows UWP is complicated due to UWP’s sandboxed runtime. You need to run an override for the sandbox to enable the injection of Dart code into the running UWP process to enable debugging and Hot Reload.

The suggested approach during development is to first run flutter run -d winuwp from the command line, which will give you a command that you need to run from a PowerShell with Administrator privileges.

PS C:\myapp> flutter run -d winuwp
Launching lib\main.dart on Windows (UWP) in debug mode...
LINK : warning LNK4075: ignoring '/INCREMENTAL' due to '/OPT:ICF' specification [C:\src\flutter-projects\myapp\build\winuwp\runner_uwp\app.vcxproj]
C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Microsoft\VisualStudio\v16.0\AppxPackage\Microsoft.AppXPackage.Targets(3327,5): warning : APPX4001: Build property AppxBundlePlatforms is not explicitly set and is calculated based on currently building architecture. Use 'Create App Package' wizard or edit project file to set it. [C:\src\flutter-projects\myapp\build\winuwp\runner_uwp\app.vcxproj]
Building Windows UWP application...
Enable Flutter debugging from localhost.

Windows UWP apps run in a sandboxed environment. To enable Flutter debugging
and hot reload, you will need to enable inbound connections to the app from the
Flutter tool running on your machine. To do so:
  1. Launch PowerShell as an Administrator
  2. Enter the following command:
     checknetisolation loopbackexempt -is -n=[APP_CONTAINER_NAME]

Press "Y" once this is complete, or "N" to abort.:

Run this checknetisolation command as shown in a PowerShell as Administrator. You can then leave this process running for the length of your development session, restarting your UWP app as required.

PS C:\> checknetisolation loopbackexempt -is -n=[APP_CONTAINER_NAME]

Network Isolation Debug Session started.
Reproduce your scenario, then press Ctrl-C when done.

Once you have this process running, you can deploy to Windows UWP from within your IDE as normal, or run from the command line as follows:

PS C:\myapp> flutter run -d winuwp

Build a release app

To generate a release build, run one of the following commands:

PS C:\> flutter build windows
$ flutter build macos
$ flutter build linux

Distribution

We don’t recommend releasing a desktop application until desktop support is stable, however, here is some information that you might still find useful.

Windows

There are various approaches you can use for distributing your Windows application. Here are some options:

  • Use tooling to construct an MSIX installer (described in the next section) for your application and distribute it through the Microsoft Windows App Store. You don’t need to manually create a signing certificate for this option as it is handled for you.
  • Construct an MSIX installer and distribute it through your own website. For this option, you need to to give your application a digital signature in the form of a .pfx certificate.
  • Collect all of the necessary pieces and build your own zip file.

MSIX packaging

MSIX, Microsoft Windows’ application package format, provides a modern packaging experience to all Windows apps. This format can either be used to ship applications to Microsoft Windows’ Apps store, or you can distribute application installers directly.

The easiest way to create an MSIX distribution for a Flutter project is to use the msix pub package. For an example of using the msix package from a Flutter desktop app, see the Desktop Photo Search sample.

Create a self-signed .pfx certificate for local testing

For private deployment and testing with the help of the MSIX installer, you need to give your application a digital signature in the form of a .pfx certificate.

For deployment through the Windows Store, generating a .pfx certificate is not required. The Windows Store handles creation and management of certificates for applications distributed through its store.

Distributing your application by self hosting it on a website requires a certificate signed by a Certificate Authority known to Windows.

Use the following instructions to generate a self-signed .pfx certificate.

  1. If you haven’t already, download the OpenSSL toolkit to generate your certificates.
  2. Go to where you installed OpenSSL, for example, C:\Program Files\OpenSSL-Win64\bin.
  3. Set an environment variable so that you can access OpenSSL from anywhere:
    "C:\Program Files\OpenSSL-Win64\bin"
  4. Generate a private key as follows:
    openssl genrsa -out mykeyname.key 2048
  5. Generate a certificate signing request (CSR) file using the private key:
    openssl req -new -key mykeyname.key -out mycsrname.csr
  6. Generate the signed certificate (CRT) file using the private key and CSR file:
    openssl x509 -in mycsrname.csr -out mycrtname.crt -req -signkey mykeyname.key -days 10000
  7. Generate the .pfx file using the private key and CRT file:
    openssl pkcs12 -export -out CERTIFICATE.pfx -inkey mykeyname.key -in mycrtname.crt
  8. Install the .pfx certificate first on the local machine in Certificate store as Trusted Root Certification Authorities before installing the app.

Building your own zip file for Windows

The Flutter executable, .exe, can be found in your project under build\windows\runner\<build mode>\. In addition to that executable, you need the following:

  • From the same directory:
    • all the .dll files
    • the data directory
  • The Visual C++ redistributables. You can use any of the methods shown in the deployment example walkthroughs on the Microsoft site to ensure that end users have the C++ redistributables. If you use the application-local option, you need to copy:
    • msvcp140.dll
    • vcruntime140.dll
    • vcruntime140_1.dll

    These 3 files can be found in C:\Windows\System32 if installed on your PC. Place the DLL files in the directory next to the executable and the other DLLs, and bundle them together in a zip file. The resulting structure will look something a little like this:

    Release
│   flutter_windows.dll
│   msvcp140.dll
│   myapp.exe
│   vcruntime140.dll
│   vcruntime140_1.dll
│
└───data
│   │   app.so
│   │   icudtl.dat

...

At this point if desired it would be relatively simple to add this folder to a Windows installer such as Inno Setup, WiX, etc.

macOS

To distribute your macOS application, you can either distribute it through the macOS App Store, or you can distribute the .app itself, perhaps from your own website. As of macOS 10.14.5, you need to notarize your macOS application before distributing it outside of the macOS App Store.

The first step in both of the above processes involves working with your application inside of Xcode. To be able to compile your application from inside of Xcode you first need to build the application for release using the flutter build command, then open the Flutter macOS Runner application.

$ flutter build macos
$ open macos/Runner.xcworkspace

Once inside of Xcode, follow either Apple’s documentation on notarizing macOS Applications, or on distributing an application through the App Store. You should also read through the macOS-specific support section below to understand how entitlements, the App Sandbox, and the Hardened Runtime impact your distributable application.

Linux

The executable binary can be found in your project under build/linux/<build mode>/bundle/. Alongside your executable binary in the bundle directory there are two directories:

  • lib contains the required .so library files
  • data contains the application’s data assets, such as fonts or images

In addition to these files, your application also relies on various operating system libraries that it’s been compiled against. You can see the full list by running ldd against your application. For example, assuming you have a Flutter desktop application called linux_desktop_test you could inspect the system libraries it depends upon as follows:

$ flutter build linux --release
$ ldd build/linux/release/bundle/linux_desktop_test

To wrap up this application for distribution you need to include everything in the bundle directory, and make sure the Linux system you are installing it upon has all of the system libraries required. This may be as simple as:

$ sudo apt-get install libgtk-3-0 libblkid1 liblzma5

For information on publishing a Linux application to the Snap Store, see Build and release a Linux application to the Snap Store.

As the tooling solidifies, stay tuned for updates on other ways to distribute a Linux desktop app.

Add desktop support to an existing Flutter app

To add desktop support to an existing Flutter project, run the following command in a terminal from the root project directory:

$ flutter create --platforms=windows,macos,linux .

This adds the necessary desktop files and directories to your existing Flutter project. To add only specific desktop platforms, change the platforms list to include only the platform(s) you want to add.

macOS-specific support

The following information applies only to macOS development.

Entitlements and the App Sandbox

macOS builds are configured by default to be signed, and sandboxed with App Sandbox. This means that if you want to confer specific capabilities or services on your macOS app, such as the following:

  • Accessing the internet
  • Capturing movies and images from the built-in camera
  • Accessing files

Then you must set up specific entitlements in Xcode. The following section tells you how to do this.

Setting up entitlements

Managing sandbox settings is done in the macos/Runner/*.entitlements files. When editing these files, you shouldn’t remove the original Runner-DebugProfile.entitlements exceptions (that support incoming network connections and JIT), as they’re necessary for the debug and profile modes to function correctly.

If you’re used to managing entitlement files through the Xcode capabilities UI, be aware that the capabilities editor updates only one of the two files or, in some cases, it creates a whole new entitlements file and switches the project to use it for all configurations. Either scenario causes issues. We recommend that you edit the files directly. Unless you have a very specific reason, you should always make identical changes to both files.

If you keep the App Sandbox enabled (which is required if you plan to distribute your application in the App Store), you need to manage entitlements for your application when you add certain plugins or other native functionality. For instance, using the file_chooser plugin requires adding either the com.apple.security.files.user-selected.read-only or com.apple.security.files.user-selected.read-write entitlement. Another common entitlement is com.apple.security.network.client, which you must add if you make any network requests.

Without the com.apple.security.network.client entitlement, for example, network requests will fail with a message such as:

flutter: SocketException: Connection failed
(OS Error: Operation not permitted, errno = 1),
address = example.com, port = 443

For more information on these topics, see App Sandbox and Entitlements on the Apple Developer site.

Hardened Runtime

If you choose to distribute your application outside of the App Store, you need to notarize your application for compatibility with macOS 10.15+. This requires enabling the Hardened Runtime option. Once you have enabled it, you need a valid signing certificate in order to build.

By default, the entitlements file allows JIT for debug builds but, as with App Sandbox, you may need to manage other entitlements. If you have both App Sandbox and Hardened Runtime enabled, you may need to add multiple entitlements for the same resource. For instance, microphone access would require both com.apple.security.device.audio-input (for Hardened Runtime) and com.apple.security.device.microphone (for App Sandbox).

For more information on this topic, see Hardened Runtime on the Apple Developer site.

Plugin support

Flutter on the desktop supports using and creating plugins.

Using a plugin

To use a plugin that supports desktop, follow the steps for plugins in using packages. Flutter automatically adds the necessary native code to your project, as with iOS or Android.

We recommend the following plugins, which have been updated to work for desktop apps:

Use the following links to find all packages on pub.dev that support desktop apps. These links lists all packages, not just plugin packages. (Remember that plugin packages, or plugins, provide an interface to platform-specific services.)

Writing a plugin

When you start building your own plugins, you’ll want to keep federation in mind. Federation is the ability to define several different packages, each targeted at a different set of platforms, brought together into a single plugin for ease of use by developers. For example, the Windows implementation of the url_launcher is really url_launcher_windows, but a Flutter developer can simply add the url_launcher package to their pubspec.yaml as a dependency and the build process pulls in the correct implementation based on the target platform. Federation is handy because different teams with different expertise can build plugin implementations for different platforms. You can add a new platform implementation to any endorsed federated plugin on pub.dev, so long as you coordinate this effort with the original plugin author.

For more information, including information about endorsed plugins, see the following resources:

Samples and codelabs

Write a Flutter desktop application
A codelab that walks you through building a desktop application that integrates the GitHub GraphQL API with your Flutter app.

You can run the following samples as desktop apps, as well as download and inspect the source code to learn more about Flutter desktop support.

Flutter Gallery running web app, repo
A samples project hosted on GitHub to help developers evaluate and use Flutter. The Gallery consists of a collection of Material design widgets, behaviors, and vignettes implemented with Flutter. You can clone the project and run Gallery as a desktop app by following the instructions provided in the README.
Flokk announcement blogpost, repo
A Google contacts manager that integrates with GitHub and Twitter. It syncs with your Google account, imports your contacts, and allows you to manage them.
Photo Search app
A sample application built as a desktop application that uses the following desktop-supported plugins: