How to create login and signup page using flutter

Let’s go step-by-step on how to create login and signup pages in Flutter, including UI, form validation, and navigation between both pages.

🧱 Step 1: Create a New Flutter Project

In your terminal or VS Code:

flutter create login_signup_app
cd login_signup_app

🧩 Step 2: Folder Structure (Recommended)

Organize your project like this:

lib/
 ┣ screens/
 ┃ ┣ login_screen.dart
 ┃ ┗ signup_screen.dart
 ┣ main.dart

🧮 Step 3: main.dart

Set up routes for navigation between login and signup pages.

import 'package:flutter/material.dart';
import 'screens/login_screen.dart';
import 'screens/signup_screen.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Login Signup Demo',
      theme: ThemeData(primarySwatch: Colors.blue),
      initialRoute: '/login',
      routes: {
        '/login': (context) => const LoginScreen(),
        '/signup': (context) => const SignupScreen(),
      },
    );
  }
}

🔐 Step 4: Create Login Screen

lib/screens/login_screen.dart

import 'package:flutter/material.dart';

class LoginScreen extends StatefulWidget {
  const LoginScreen({super.key});

  @override
  State<LoginScreen> createState() => _LoginScreenState();
}

class _LoginScreenState extends State<LoginScreen> {
  final _formKey = GlobalKey<FormState>();
  final emailController = TextEditingController();
  final passwordController = TextEditingController();

  void login() {
    if (_formKey.currentState!.validate()) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Logging in...')),
      );
      // TODO: Add Firebase or API login logic here
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Login')),
      body: Padding(
        padding: const EdgeInsets.all(16),
        child: Form(
          key: _formKey,
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              TextFormField(
                controller: emailController,
                decoration: const InputDecoration(labelText: 'Email'),
                validator: (value) =>
                    value!.isEmpty ? 'Please enter email' : null,
              ),
              const SizedBox(height: 10),
              TextFormField(
                controller: passwordController,
                decoration: const InputDecoration(labelText: 'Password'),
                obscureText: true,
                validator: (value) =>
                    value!.isEmpty ? 'Please enter password' : null,
              ),
              const SizedBox(height: 20),
              ElevatedButton(
                onPressed: login,
                child: const Text('Login'),
              ),
              TextButton(
                onPressed: () {
                  Navigator.pushReplacementNamed(context, '/signup');
                },
                child: const Text("Don't have an account? Sign up"),
              )
            ],
          ),
        ),
      ),
    );
  }
}

📝 Step 5: Create Signup Screen

lib/screens/signup_screen.dart

import 'package:flutter/material.dart';

class SignupScreen extends StatefulWidget {
  const SignupScreen({super.key});

  @override
  State<SignupScreen> createState() => _SignupScreenState();
}

class _SignupScreenState extends State<SignupScreen> {
  final _formKey = GlobalKey<FormState>();
  final nameController = TextEditingController();
  final emailController = TextEditingController();
  final passwordController = TextEditingController();

  void signup() {
    if (_formKey.currentState!.validate()) {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(content: Text('Signing up...')),
      );
      // TODO: Add Firebase or API signup logic here
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Signup')),
      body: Padding(
        padding: const EdgeInsets.all(16),
        child: Form(
          key: _formKey,
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              TextFormField(
                controller: nameController,
                decoration: const InputDecoration(labelText: 'Full Name'),
                validator: (value) =>
                    value!.isEmpty ? 'Please enter your name' : null,
              ),
              const SizedBox(height: 10),
              TextFormField(
                controller: emailController,
                decoration: const InputDecoration(labelText: 'Email'),
                validator: (value) =>
                    value!.isEmpty ? 'Please enter email' : null,
              ),
              const SizedBox(height: 10),
              TextFormField(
                controller: passwordController,
                decoration: const InputDecoration(labelText: 'Password'),
                obscureText: true,
                validator: (value) =>
                    value!.isEmpty ? 'Please enter password' : null,
              ),
              const SizedBox(height: 20),
              ElevatedButton(
                onPressed: signup,
                child: const Text('Sign Up'),
              ),
              TextButton(
                onPressed: () {
                  Navigator.pushReplacementNamed(context, '/login');
                },
                child: const Text("Already have an account? Login"),
              )
            ],
          ),
        ),
      ),
    );
  }
}

🚀 Step 6: Run the App

flutter run

You’ll see a simple Login Page → Signup Page navigation working with form validation.

💡 Next Steps

To make it production-ready:

1. Add Firebase Authentication → [I can show you step-by-step setup next]
2. Use Bloc or Provider for managing auth state.
3. Use SharedPreferences or SecureStorage for saving user sessions.
4. Add email/password validation, loading indicators, and error handling.