How to navigate to other page without animation Flutter

Question

You can use PageRouteBuilder.

Navigator.pushReplacement(
    context, 
    PageRouteBuilder(
        pageBuilder: (context, animation1, animation2) => Page1(),
        transitionDuration: Duration.zero,
    ),
);

You would need to override the buildTransitions method to prevent animations.

import 'package:flutter/material.dart';

class NoAnimationMaterialPageRoute<T> extends MaterialPageRoute<T> {
  NoAnimationMaterialPageRoute({
    @required WidgetBuilder builder,
    RouteSettings settings,
    bool maintainState = true,
    bool fullscreenDialog = false,
  }) : super(
            builder: builder,
            maintainState: maintainState,
            settings: settings,
            fullscreenDialog: fullscreenDialog);

  @override
  Widget buildTransitions(BuildContext context, Animation<double> animation,
      Animation<double> secondaryAnimation, Widget child) {
    return child;
  }
}

For Null safety:

import 'package:flutter/material.dart';

class NoAnimationMaterialPageRoute<T> extends MaterialPageRoute<T> {
  NoAnimationMaterialPageRoute({
    required WidgetBuilder builder,
    RouteSettings? settings,
    bool maintainState = true,
    bool fullscreenDialog = false,
  }) : super(
            builder: builder,
            maintainState: maintainState,
            settings: settings,
            fullscreenDialog: fullscreenDialog);

  @override
  Widget buildTransitions(BuildContext context, Animation<double> animation,
      Animation<double> secondaryAnimation, Widget child) {
    return child;
  }
}

Make sure you also set transitionDuration otherwise you may push the new route without animation but when you press back button, you'll see some delay.

Navigator.push(
  context,
  PageRouteBuilder(
    pageBuilder: (_, __, ___) => Screen2(),
    transitionDuration: Duration(seconds: 0),
  ),
);

You can override MaterialPageRoute to set transitionDuration to zero

class CustomPageRoute extends MaterialPageRoute {
  CustomPageRoute({builder}) : super(builder: builder);

  @override
  Duration get transitionDuration => const Duration(milliseconds: 0);
}

...

Navigator.of(context).push(
  CustomPageRoute(
    builder: (BuildContext context) {
      return DashboardView();
    },
  ),
);

My solution is to define the route with isInitialRoute:true. This prevents Flutter from showing an animation when the route is pushed.

Here's a working example and screen recording:

import 'package:flutter/cupertino.dart'
    show
        CupertinoApp,
        CupertinoButton,
        CupertinoPageRoute,
        CupertinoPageScaffold;
import 'package:flutter/widgets.dart'
    show
        BuildContext,
        Center,
        Column,
        Navigator,
        Route,
        RouteSettings,
        SafeArea,
        Spacer,
        Text,
        runApp,
        Widget;

Widget makeButton(BuildContext context, String routeName) =>
    new CupertinoButton(
      onPressed: () => Navigator.pushReplacementNamed(context, routeName),
      child: Text('Go to \'$routeName\''),
    );

Route generateRoute(RouteSettings settings) {
  switch (settings.name) {
    case 'not-animated':
      return new CupertinoPageRoute(
        settings: RouteSettings(name: settings.name, isInitialRoute: true),
        builder: (context) => CupertinoPageScaffold(
              child: SafeArea(
                child: Center(
                  child: Column(
                    children: [
                      Spacer(),
                      Text('This is \'not-animated\''),
                      makeButton(context, 'animated'),
                      Spacer(),
                    ],
                  ),
                ),
              ),
            ),
      );
    default:
      return null;
  }
}

void main() {
  runApp(
    CupertinoApp(
      onGenerateRoute: generateRoute,
      initialRoute: 'animated',
      routes: {
        'animated': (context) => CupertinoPageScaffold(
              child: SafeArea(
                child: Center(
                  child: Column(
                    children: [
                      Spacer(),
                      Text('This is \'animated\''),
                      makeButton(context, 'not-animated'),
                      Spacer(),
                    ],
                  ),
                ),
              ),
            ),
      },
    ),
  );
}

You should try to extend MaterialPageRoute and override buildTransitions as follows:

class ExPageRoute<T> extends MaterialPageRoute<T> {

 @override
 Widget buildTransitions(BuildContext context, Animation<double> animation,
    Animation<double> secondaryAnimation, Widget child) {
    return child;
 }
}