SimWin compiles your Flutter app into a real Windows .exe on your Mac and runs it in a Windows 11-style simulator.
Pick SimWin · Windows 11 in VS Code or Android Studio and press Run. No PC, no virtual machine.
[!NOTE]
SimWin is in beta (version 0.0.2) and makes debug builds only. It works for everyday debugging with hot reload,
breakpoints and DevTools, but expect rough edges. Release and profile builds aren't supported yet.
Please report anything that goes wrong.
A real Windows app, not a look-alike
SimWin isn't a Mac app made to look like Windows. It cross-compiles your Flutter project into a genuine Windows executable
and runs that exact file, so you test the code your Windows users get.
$ ls out/
simwin_sample.exe flutter_windows.dll data/
$ file out/simwin_sample.exe
simwin_sample.exe: PE32+ executable (GUI) x86-64, for MS Windows
- Compiled for Windows. A Windows x64 cross-compiler on your Mac compiles your runner and plugins into a 64-bit Windows executable.
- Flutter's Windows engine. Your Dart code runs on
flutter_windows.dll, the same engine flutter build windows uses, not Flutter's macOS engine.
- Windows code paths run.
Platform.isWindows is true, paths are C:\…, and your plugins' Win32 C++ code is compiled and called.
- Not a VM, not a look-alike. A compatibility layer runs the
.exe by translating its Windows API calls to macOS. There is no copy of Windows and no Mac version of your app.
Install
curl -fsSL https://simwin.dev/install.sh | bash
This downloads, verifies and installs SimWin, adds the simwin command, and runs setup.
Or download the DMG, drag SimWin to Applications and open it.
Setup downloads the build tools (about 400 MB) and checks everything with a sample app. It takes about five minutes, once.
| Requirements |
|---|
| macOS | 14 Sonoma or later |
| Processor | Apple Silicon (with Rosetta 2, which setup installs) or Intel |
| Flutter | Stable channel, 3.45 – 3.47 |
| IDE | VS Code with the Flutter extension, Android Studio or IntelliJ, or just Terminal |
| Storage | About 3 GB after setup, plus build caches |
SimWin is signed with Developer ID, notarized by Apple, and keeps itself up to date.
What SimWin does
- The real Windows build. Compiled for Windows x64 on your Mac.
Platform.isWindows is true, paths are C:\…, and your Windows plugin code runs.
- A device in your IDE. "SimWin · Windows 11" shows up in VS Code, Android Studio and
flutter devices, just like an emulator.
- Hot reload and DevTools. Debug mode with hot reload, hot restart, breakpoints and Flutter DevTools, as on a Windows PC.
- A Windows-style desktop. Your app runs on a desktop with a taskbar, a Start menu and a real Windows title bar: minimise, maximise and close behave as on Windows. Apps you've run appear as desktop icons.
- Wi-Fi switch. Turn Wi-Fi off from the taskbar (or
simwin network off) to test offline handling. Your debugger stays connected.
- Simulator toolbar. Display scale from 100 to 200 %, window size, light or dark mode, and locale, including right-to-left.
- Screenshots and recordings. Capture the app window as PNG or video, from the toolbar, the menu bar or the command line.
- Profiles. Save combinations of scale, size, theme and locale, then switch between them in one click.
- Plugins that compile. Windows plugin code is built with clang. Plugins that need Visual Studio-only tools are named, not left to fail silently.
- Command line.
simwin open, simwin screenshot and simwin doctor work in Terminal and scripts, no IDE needed.
- Your project stays untouched. SimWin builds from a private copy. It never edits your files, pubspec or Git state.
How it works
- Install and set up SimWin (above).
- Pick the device. Open your Flutter project in VS Code or Android Studio and choose SimWin · Windows 11.
- Press Run. SimWin builds the Windows app and opens it in the simulator. Edit your code and hot reload as usual.
What happens when you press Run:
| Step | |
|---|
| Your project | Copied to a private staging folder. The original is never changed. |
| Compiled for Windows x64 | A Windows x64 cross-compiler, with Flutter's Windows engine. |
my_app.exe | The same debug build a Windows PC would produce. |
| Runs on your Mac | Through a compatibility layer, not a VM. Graphics are translated to Metal. |
| Connected to your IDE | Over the Dart VM service: hot reload, breakpoints, DevTools. |
The first build of a project takes a few minutes, while SimWin fetches Flutter's Windows engine files and compiles everything.
After that, builds are incremental and hot reload takes well under a second.
Command line
simwin open path/to/project # build and run without an IDE
simwin stop # stop the running app
simwin screenshot --output shot.png # save the app window as PNG
simwin profile list | use | create | set # scale, size, theme and locale
simwin network on | off # the simulator's Wi-Fi
simwin doctor # check everything, with a fix for each problem
simwin report # create a problem report to send to us
Run simwin help <command> for the options.
Coming later
SimWin starts with Flutter. Later, we plan to support other frameworks that can build Windows apps, so you can test those on your Mac in the same way.
| Framework | Status |
|---|
| Flutter | Available in beta |
| Kotlin Multiplatform | Planned |
| Compose Multiplatform | Planned |
| React Native (React Native for Windows) | Planned |
Plans can change; we'll add each framework once its Windows builds run well in SimWin.
This is the beginning of the README. Read the rest at the original. Read the full README ↗
