How to Lock Screen Orientation in Flutter

Many developers who want to lock screen orientation in Flutter go straight to AndroidManifest.xml and add android:screenOrientation="portrait". That works, but there’s a better way.

The Dart approach: SystemChrome

Add the import and configure the orientations at the beginning of main(), before calling runApp:

import 'package:flutter/services.dart'; // ← required import

void main() {
  WidgetsFlutterBinding.ensureInitialized(); // needed before any system call
  SystemChrome.setPreferredOrientations([
    DeviceOrientation.portraitUp,
    DeviceOrientation.portraitDown,
  ]);
  runApp(const MyApp());
}

WidgetsFlutterBinding.ensureInitialized() is required to make sure Flutter is ready before any system call. Without it, setPreferredOrientations may not work correctly.

Variants

Portrait only (no upside-down):

SystemChrome.setPreferredOrientations([
  DeviceOrientation.portraitUp,
]);

Landscape only:

SystemChrome.setPreferredOrientations([
  DeviceOrientation.landscapeLeft,
  DeviceOrientation.landscapeRight,
]);

Allow all orientations:

SystemChrome.setPreferredOrientations(DeviceOrientation.values);

Why not use AndroidManifest?

The real advantage of SystemChrome shows when you need different behavior per screen, for example: lock portrait app-wide but unlock landscape for a specific video player or minigame. Just call setPreferredOrientations again on that screen.

For locking the whole app to portrait, both approaches work. But the Dart way handles it cleanly and covers iOS for free.