How can I run release build of my Flutter app on Simulator

No, You can't run release build on Emulator. You need a actual device to run release build and ios devices won't support release build.

If you want to remove the debug banner from your app,

Add this line in your MaterialApp

debugShowCheckedModeBanner:false,

To run release build on android devices

flutter run --release

To get release build on your storage

flutter build apk --release

This will generate a release build, If you want to get a normal build run below command

flutter run

If you want to get ios build you should run this command ( you can't run this command on Windows and LINUX computers, You need a MAC system for get ios build )

flutter build ios

I hope this will help someone who new to flutter

The command flutter run --release compiles to release mode.

To remove "debug banner" you can use debugShowCheckedModeBanner property of MaterialApp() widget. If you set this property to false , banner will be disappeared.

class MyApp extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
        return MaterialApp(
            home: HomePage(),
            debugShowCheckedModeBanner: false,
        );
    }
}

You won't be able to run release mode on simulator as it only runs on actual device.

However you can remove the debug banner by passing debugShowCheckedModeBanner:false in your MaterialApp()

MaterialApp(
  debugShowCheckedModeBanner:false,
  home:...
)