Flutter or React Native: Which One Is Better for SaaS Apps?

Choosing the right technology stack can make or break your SaaS product, especially when time-to-market, maintainability, and cross-platform consistency are critical business requirements. Flutter and React Native stand out as the most popular frameworks for building modern, high-performance cross-platform applications.

But which one is better for SaaS apps in 2025? In this comprehensive comparison, we’ll examine Flutter vs. React Native from a SaaS development perspective, including real code examples demonstrating common SaaS patterns like authentication, state management, API integration, and subscription handling.

Why This Decision Matters for SaaS

SaaS applications have unique requirements that differentiate them from typical mobile apps:

• Fast time-to-market – Iterate quickly on features
• Consistent UI across platforms – iOS, Android, Web, Desktop
• Real-time features – Live data, chat, notifications
• Complex state management – Multi-tenant data, user roles, subscriptions
• Third-party integrations – Payments, analytics, authentication
• Offline support – Work without internet connectivity

The wrong framework choice can lead to costly rewrites, slow iteration cycles, or poor user experiences that hurt conversion.

Flutter vs. React Native: SaaS-Focused Comparison

Authentication Implementation Comparison

Every SaaS app needs robust authentication. Let’s compare how each framework handles OAuth and token management.

Flutter Authentication with Riverpod:

// lib/providers/auth_provider.dart
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter_secure_storage/flutter_secure_storage.dart';
import '../models/user.dart';
import '../services/auth_service.dart';

enum AuthStatus { initial, loading, authenticated, unauthenticated, error }

class AuthState {
  final AuthStatus status;
  final User? user;
  final String? error;
  final String? accessToken;

  const AuthState({
    this.status = AuthStatus.initial,
    this.user,
    this.error,
    this.accessToken,
  });

  AuthState copyWith({
    AuthStatus? status,
    User? user,
    String? error,
    String? accessToken,
  }) {
    return AuthState(
      status: status ?? this.status,
      user: user ?? this.user,
      error: error ?? this.error,
      accessToken: accessToken ?? this.accessToken,
    );
  }
}

class AuthNotifier extends StateNotifier<AuthState> {
  final AuthService _authService;
  final FlutterSecureStorage _storage;

  AuthNotifier(this._authService, this._storage) : super(const AuthState()) {
    _checkAuthStatus();
  }

  Future<void> _checkAuthStatus() async {
    final token = await _storage.read(key: 'access_token');
    if (token != null) {
      try {
        final user = await _authService.getCurrentUser(token);
        state = AuthState(
          status: AuthStatus.authenticated,
          user: user,
          accessToken: token,
        );
      } catch (e) {
        await _storage.delete(key: 'access_token');
        state = const AuthState(status: AuthStatus.unauthenticated);
      }
    } else {
      state = const AuthState(status: AuthStatus.unauthenticated);
    }
  }

  Future<void> login(String email, String password) async {
    state = state.copyWith(status: AuthStatus.loading);
    try {
      final result = await _authService.login(email, password);
      await _storage.write(key: 'access_token', value: result.accessToken);
      await _storage.write(key: 'refresh_token', value: result.refreshToken);
      state = AuthState(
        status: AuthStatus.authenticated,
        user: result.user,
        accessToken: result.accessToken,
      );
    } catch (e) {
      state = AuthState(
        status: AuthStatus.error,
        error: e.toString(),
      );
    }
  }

  Future<void> logout() async {
    await _storage.deleteAll();
    state = const AuthState(status: AuthStatus.unauthenticated);
  }

  Future<void> refreshToken() async {
    final refreshToken = await _storage.read(key: 'refresh_token');
    if (refreshToken == null) {
      await logout();
      return;
    }
    try {
      final newToken = await _authService.refreshToken(refreshToken);
      await _storage.write(key: 'access_token', value: newToken);
      state = state.copyWith(accessToken: newToken);
    } catch (e) {
      await logout();
    }
  }
}

final authProvider = StateNotifierProvider<AuthNotifier, AuthState>((ref) {
  return AuthNotifier(
    ref.read(authServiceProvider),
    const FlutterSecureStorage(),
  );
});

React Native Authentication with Redux Toolkit:

// src/store/slices/authSlice.ts
import { createSlice, createAsyncThunk, PayloadAction } from '@reduxjs/toolkit';
import * as SecureStore from 'expo-secure-store';
import { authApi } from '../../services/authApi';
import { User } from '../../types/user';

interface AuthState {
  status: 'initial' | 'loading' | 'authenticated' | 'unauthenticated' | 'error';
  user: User | null;
  accessToken: string | null;
  error: string | null;
}

const initialState: AuthState = {
  status: 'initial',
  user: null,
  accessToken: null,
  error: null,
};

export const checkAuthStatus = createAsyncThunk(
  'auth/checkStatus',
  async (_, { rejectWithValue }) => {
    try {
      const token = await SecureStore.getItemAsync('access_token');
      if (!token) return null;
      const user = await authApi.getCurrentUser(token);
      return { user, accessToken: token };
    } catch (error) {
      await SecureStore.deleteItemAsync('access_token');
      return rejectWithValue('Session expired');
    }
  }
);

export const login = createAsyncThunk(
  'auth/login',
  async (
    { email, password }: { email: string; password: string },
    { rejectWithValue }
  ) => {
    try {
      const result = await authApi.login(email, password);
      await SecureStore.setItemAsync('access_token', result.accessToken);
      await SecureStore.setItemAsync('refresh_token', result.refreshToken);
      return result;
    } catch (error: any) {
      return rejectWithValue(error.message || 'Login failed');
    }
  }
);

export const logout = createAsyncThunk('auth/logout', async () => {
  await SecureStore.deleteItemAsync('access_token');
  await SecureStore.deleteItemAsync('refresh_token');
});

export const refreshToken = createAsyncThunk(
  'auth/refresh',
  async (_, { rejectWithValue, dispatch }) => {
    try {
      const token = await SecureStore.getItemAsync('refresh_token');
      if (!token) throw new Error('No refresh token');
      const newToken = await authApi.refreshToken(token);
      await SecureStore.setItemAsync('access_token', newToken);
      return newToken;
    } catch (error) {
      dispatch(logout());
      return rejectWithValue('Session expired');
    }
  }
);

const authSlice = createSlice({
  name: 'auth',
  initialState,
  reducers: {
    clearError: (state) => {
      state.error = null;
    },
  },
  extraReducers: (builder) => {
    builder
      .addCase(checkAuthStatus.fulfilled, (state, action) => {
        if (action.payload) {
          state.status = 'authenticated';
          state.user = action.payload.user;
          state.accessToken = action.payload.accessToken;
        } else {
          state.status = 'unauthenticated';
        }
      })
      .addCase(login.pending, (state) => {
        state.status = 'loading';
        state.error = null;
      })
      .addCase(login.fulfilled, (state, action) => {
        state.status = 'authenticated';
        state.user = action.payload.user;
        state.accessToken = action.payload.accessToken;
      })
      .addCase(login.rejected, (state, action) => {
        state.status = 'error';
        state.error = action.payload as string;
      })
      .addCase(logout.fulfilled, (state) => {
        state.status = 'unauthenticated';
        state.user = null;
        state.accessToken = null;
      })
      .addCase(refreshToken.fulfilled, (state, action) => {
        state.accessToken = action.payload;
      });
  },
});

export const { clearError } = authSlice.actions;
export default authSlice.reducer;

Subscription Management for SaaS

Subscription handling is critical for SaaS monetization. Here’s how each framework integrates with payment providers.

Flutter Subscription Screen with Stripe:

// lib/screens/subscription_screen.dart
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../providers/subscription_provider.dart';
import '../models/plan.dart';

class SubscriptionScreen extends ConsumerWidget {
  const SubscriptionScreen({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final subscriptionState = ref.watch(subscriptionProvider);
    final plans = ref.watch(plansProvider);

    return Scaffold(
      appBar: AppBar(title: const Text('Choose Your Plan')),
      body: plans.when(
        loading: () => const Center(child: CircularProgressIndicator()),
        error: (e, _) => Center(child: Text('Error: $e')),
        data: (planList) => Column(
          children: [
            // Current subscription banner
            if (subscriptionState.currentPlan != null)
              Container(
                padding: const EdgeInsets.all(16),
                color: Theme.of(context).primaryColor.withOpacity(0.1),
                child: Row(
                  children: [
                    const Icon(Icons.check_circle, color: Colors.green),
                    const SizedBox(width: 8),
                    Expanded(
                      child: Text(
                        'Current plan: ${subscriptionState.currentPlan!.name}',
                        style: const TextStyle(fontWeight: FontWeight.bold),
                      ),
                    ),
                    if (subscriptionState.isTrialing)
                      Chip(
                        label: Text(
                          '${subscriptionState.trialDaysRemaining} days left',
                        ),
                        backgroundColor: Colors.orange,
                      ),
                  ],
                ),
              ),
            // Plan cards
            Expanded(
              child: ListView.builder(
                padding: const EdgeInsets.all(16),
                itemCount: planList.length,
                itemBuilder: (context, index) {
                  final plan = planList[index];
                  final isCurrentPlan =
                      subscriptionState.currentPlan?.id == plan.id;
                  return PlanCard(
                    plan: plan,
                    isCurrentPlan: isCurrentPlan,
                    isPopular: plan.metadata['popular'] == 'true',
                    onSelect: isCurrentPlan
                        ? null
                        : () => _handlePlanSelection(context, ref, plan),
                  );
                },
              ),
            ),
          ],
        ),
      ),
    );
  }

  Future<void> _handlePlanSelection(
    BuildContext context,
    WidgetRef ref,
    Plan plan,
  ) async {
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: Text('Subscribe to ${plan.name}'),
        content: Text(
          'You will be charged \$${(plan.amount / 100).toStringAsFixed(2)}/${plan.interval}',
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context, false),
            child: const Text('Cancel'),
          ),
          ElevatedButton(
            onPressed: () => Navigator.pop(context, true),
            child: const Text('Subscribe'),
          ),
        ],
      ),
    );

    if (confirmed == true) {
      await ref.read(subscriptionProvider.notifier).subscribe(plan.id);
    }
  }
}

class PlanCard extends StatelessWidget {
  final Plan plan;
  final bool isCurrentPlan;
  final bool isPopular;
  final VoidCallback? onSelect;

  const PlanCard({
    required this.plan,
    required this.isCurrentPlan,
    required this.isPopular,
    this.onSelect,
    super.key,
  });

  @override
  Widget build(BuildContext context) {
    return Card(
      elevation: isPopular ? 8 : 2,
      margin: const EdgeInsets.only(bottom: 16),
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(12),
        side: isPopular
            ? BorderSide(color: Theme.of(context).primaryColor, width: 2)
            : BorderSide.none,
      ),
      child: Padding(
        padding: const EdgeInsets.all(20),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                Text(
                  plan.name,
                  style: Theme.of(context).textTheme.headlineSmall,
                ),
                if (isPopular)
                  Container(
                    padding: const EdgeInsets.symmetric(
                      horizontal: 12,
                      vertical: 4,
                    ),
                    decoration: BoxDecoration(
                      color: Theme.of(context).primaryColor,
                      borderRadius: BorderRadius.circular(20),
                    ),
                    child: const Text(
                      'POPULAR',
                      style: TextStyle(
                        color: Colors.white,
                        fontSize: 12,
                        fontWeight: FontWeight.bold,
                      ),
                    ),
                  ),
              ],
            ),
            const SizedBox(height: 8),
            RichText(
              text: TextSpan(
                style: Theme.of(context).textTheme.headlineMedium,
                children: [
                  TextSpan(
                    text: '\$${(plan.amount / 100).toStringAsFixed(0)}',
                    style: const TextStyle(fontWeight: FontWeight.bold),
                  ),
                  TextSpan(
                    text: '/${plan.interval}',
                    style: Theme.of(context).textTheme.bodyMedium,
                  ),
                ],
              ),
            ),
            const SizedBox(height: 16),
            ...plan.features.map(
              (feature) => Padding(
                padding: const EdgeInsets.only(bottom: 8),
                child: Row(
                  children: [
                    const Icon(Icons.check, color: Colors.green, size: 20),
                    const SizedBox(width: 8),
                    Expanded(child: Text(feature)),
                  ],
                ),
              ),
            ),
            const SizedBox(height: 16),
            SizedBox(
              width: double.infinity,
              child: ElevatedButton(
                onPressed: onSelect,
                style: ElevatedButton.styleFrom(
                  backgroundColor: isCurrentPlan ? Colors.grey : null,
                ),
                child: Text(isCurrentPlan ? 'Current Plan' : 'Select Plan'),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

React Native Subscription with RevenueCat:

// src/screens/SubscriptionScreen.tsx
import React, { useEffect, useState } from 'react';
import {
  View,
  Text,
  StyleSheet,
  ScrollView,
  TouchableOpacity,
  Alert,
  ActivityIndicator,
} from 'react-native';
import Purchases, { PurchasesPackage } from 'react-native-purchases';
import { useSelector, useDispatch } from 'react-redux';
import { RootState } from '../store';
import { updateSubscription } from '../store/slices/subscriptionSlice';
import { PlanCard } from '../components/PlanCard';

export const SubscriptionScreen: React.FC = () => {
  const [packages, setPackages] = useState<PurchasesPackage[]>([]);
  const [loading, setLoading] = useState(true);
  const [purchasing, setPurchasing] = useState(false);
  const subscription = useSelector((state: RootState) => state.subscription);
  const dispatch = useDispatch();

  useEffect(() => {
    loadOfferings();
  }, []);

  const loadOfferings = async () => {
    try {
      const offerings = await Purchases.getOfferings();
      if (offerings.current?.availablePackages) {
        setPackages(offerings.current.availablePackages);
      }
    } catch (error) {
      console.error('Error loading offerings:', error);
    } finally {
      setLoading(false);
    }
  };

  const handlePurchase = async (pkg: PurchasesPackage) => {
    Alert.alert(
      `Subscribe to ${pkg.product.title}`,
      `You will be charged ${pkg.product.priceString}/${pkg.packageType === 'ANNUAL' ? 'year' : 'month'}`,
      [
        { text: 'Cancel', style: 'cancel' },
        {
          text: 'Subscribe',
          onPress: async () => {
            setPurchasing(true);
            try {
              const purchaserInfo = await Purchases.purchasePackage(pkg);
              const isSubscribed =
                purchaserInfo.entitlements.active['premium'] !== undefined;
              if (isSubscribed) {
                dispatch(
                  updateSubscription({
                    planId: pkg.identifier,
                    status: 'active',
                    expiresAt:
                      purchaserInfo.entitlements.active['premium']?.expirationDate,
                  })
                );
                Alert.alert('Success', 'Welcome to Premium!');
              }
            } catch (error: any) {
              if (!error.userCancelled) {
                Alert.alert('Error', 'Purchase failed. Please try again.');
              }
            } finally {
              setPurchasing(false);
            }
          },
        },
      ]
    );
  };

  const handleRestore = async () => {
    setLoading(true);
    try {
      const purchaserInfo = await Purchases.restorePurchases();
      const isSubscribed =
        purchaserInfo.entitlements.active['premium'] !== undefined;
      if (isSubscribed) {
        Alert.alert('Restored', 'Your subscription has been restored!');
      } else {
        Alert.alert('No Subscription', 'No active subscription found.');
      }
    } catch (error) {
      Alert.alert('Error', 'Could not restore purchases.');
    } finally {
      setLoading(false);
    }
  };

  if (loading) {
    return (
      <View style={styles.centered}>
        <ActivityIndicator size="large" />
      </View>
    );
  }

  return (
    <ScrollView style={styles.container}>
      {subscription.isTrialing && (
        <View style={styles.trialBanner}>
          <Text style={styles.trialText}>
            {subscription.trialDaysRemaining} days left in your trial
          </Text>
        </View>
      )}

      <Text style={styles.title}>Choose Your Plan</Text>

      {packages.map((pkg) => (
        <PlanCard
          key={pkg.identifier}
          package={pkg}
          isCurrentPlan={subscription.planId === pkg.identifier}
          onSelect={() => handlePurchase(pkg)}
          disabled={purchasing}
        />
      ))}

      <TouchableOpacity style={styles.restoreButton} onPress={handleRestore}>
        <Text style={styles.restoreText}>Restore Purchases</Text>
      </TouchableOpacity>
    </ScrollView>
  );
};

const styles = StyleSheet.create({
  container: { flex: 1, padding: 16 },
  centered: { flex: 1, justifyContent: 'center', alignItems: 'center' },
  title: { fontSize: 24, fontWeight: 'bold', marginBottom: 20 },
  trialBanner: {
    backgroundColor: '#FFA500',
    padding: 12,
    borderRadius: 8,
    marginBottom: 16,
  },
  trialText: { color: 'white', fontWeight: 'bold', textAlign: 'center' },
  restoreButton: { padding: 16, alignItems: 'center' },
  restoreText: { color: '#007AFF', fontSize: 16 },
});

Real-Time Features Implementation

SaaS apps often need real-time updates for notifications, collaboration, or live data. Here’s how each framework handles WebSocket connections.

Flutter WebSocket Service:

// lib/services/websocket_service.dart
import 'dart:async';
import 'dart:convert';
import 'package:web_socket_channel/web_socket_channel.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

class WebSocketService {
  WebSocketChannel? _channel;
  final _messageController = StreamController<Map<String, dynamic>>.broadcast();
  Timer? _heartbeatTimer;
  Timer? _reconnectTimer;
  bool _isConnected = false;
  String? _authToken;

  Stream<Map<String, dynamic>> get messages => _messageController.stream;
  bool get isConnected => _isConnected;

  Future<void> connect(String authToken) async {
    _authToken = authToken;
    await _establishConnection();
  }

  Future<void> _establishConnection() async {
    try {
      final uri = Uri.parse(
        'wss://api.yourapp.com/ws?token=$_authToken',
      );
      _channel = WebSocketChannel.connect(uri);

      _channel!.stream.listen(
        (data) {
          final message = jsonDecode(data) as Map<String, dynamic>;
          if (message['type'] == 'pong') return; // Heartbeat response
          _messageController.add(message);
        },
        onDone: _handleDisconnect,
        onError: (error) => _handleDisconnect(),
      );

      _isConnected = true;
      _startHeartbeat();
    } catch (e) {
      _scheduleReconnect();
    }
  }

  void _startHeartbeat() {
    _heartbeatTimer?.cancel();
    _heartbeatTimer = Timer.periodic(const Duration(seconds: 30), (_) {
      send({'type': 'ping'});
    });
  }

  void _handleDisconnect() {
    _isConnected = false;
    _heartbeatTimer?.cancel();
    _scheduleReconnect();
  }

  void _scheduleReconnect() {
    _reconnectTimer?.cancel();
    _reconnectTimer = Timer(const Duration(seconds: 5), () {
      if (_authToken != null) _establishConnection();
    });
  }

  void send(Map<String, dynamic> message) {
    if (_isConnected) {
      _channel?.sink.add(jsonEncode(message));
    }
  }

  void subscribe(String channel) {
    send({'type': 'subscribe', 'channel': channel});
  }

  void unsubscribe(String channel) {
    send({'type': 'unsubscribe', 'channel': channel});
  }

  void disconnect() {
    _heartbeatTimer?.cancel();
    _reconnectTimer?.cancel();
    _channel?.sink.close();
    _isConnected = false;
  }
}

final webSocketServiceProvider = Provider((ref) => WebSocketService());

React Native WebSocket with Auto-Reconnect:

// src/services/WebSocketService.ts
import { EventEmitter } from 'events';

type MessageHandler = (data: any) => void;

class WebSocketService extends EventEmitter {
  private ws: WebSocket | null = null;
  private authToken: string | null = null;
  private reconnectTimeout: ReturnType<typeof setTimeout> | null = null;
  private heartbeatInterval: ReturnType<typeof setInterval> | null = null;
  private subscriptions = new Set<string>();

  connect(authToken: string): void {
    this.authToken = authToken;
    this.establishConnection();
  }

  private establishConnection(): void {
    if (!this.authToken) return;

    this.ws = new WebSocket(
      `wss://api.yourapp.com/ws?token=${this.authToken}`
    );

    this.ws.onopen = () => {
      this.emit('connected');
      this.startHeartbeat();
      // Resubscribe to channels after reconnect
      this.subscriptions.forEach((channel) => this.subscribe(channel));
    };

    this.ws.onmessage = (event) => {
      const message = JSON.parse(event.data);
      if (message.type === 'pong') return;
      this.emit('message', message);
      if (message.channel) {
        this.emit(`channel:${message.channel}`, message.data);
      }
    };

    this.ws.onclose = () => this.handleDisconnect();
    this.ws.onerror = () => this.handleDisconnect();
  }

  private startHeartbeat(): void {
    this.heartbeatInterval = setInterval(() => {
      this.send({ type: 'ping' });
    }, 30000);
  }

  private handleDisconnect(): void {
    this.emit('disconnected');
    if (this.heartbeatInterval) clearInterval(this.heartbeatInterval);
    this.scheduleReconnect();
  }

  private scheduleReconnect(): void {
    if (this.reconnectTimeout) clearTimeout(this.reconnectTimeout);
    this.reconnectTimeout = setTimeout(() => {
      if (this.authToken) this.establishConnection();
    }, 5000);
  }

  send(message: object): void {
    if (this.ws?.readyState === WebSocket.OPEN) {
      this.ws.send(JSON.stringify(message));
    }
  }

  subscribe(channel: string): void {
    this.subscriptions.add(channel);
    this.send({ type: 'subscribe', channel });
  }

  unsubscribe(channel: string): void {
    this.subscriptions.delete(channel);
    this.send({ type: 'unsubscribe', channel });
  }

  onChannel(channel: string, handler: MessageHandler): () => void {
    this.on(`channel:${channel}`, handler);
    return () => this.off(`channel:${channel}`, handler);
  }

  disconnect(): void {
    if (this.heartbeatInterval) clearInterval(this.heartbeatInterval);
    if (this.reconnectTimeout) clearTimeout(this.reconnectTimeout);
    this.ws?.close();
    this.subscriptions.clear();
  }
}

export const webSocketService = new WebSocketService();

API Layer Architecture

SaaS apps require robust API handling with authentication, error handling, and retry logic.

Flutter API Client with Dio:

// lib/services/api_client.dart
import 'package:dio/dio.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../providers/auth_provider.dart';

class ApiClient {
  late final Dio _dio;
  final Ref _ref;

  ApiClient(this._ref) {
    _dio = Dio(BaseOptions(
      baseUrl: 'https://api.yourapp.com/v1',
      connectTimeout: const Duration(seconds: 10),
      receiveTimeout: const Duration(seconds: 30),
      headers: {'Content-Type': 'application/json'},
    ));

    _dio.interceptors.addAll([
      _AuthInterceptor(_ref),
      _RetryInterceptor(_dio),
      LogInterceptor(requestBody: true, responseBody: true),
    ]);
  }

  Future<T> get<T>(
    String path, {
    Map<String, dynamic>? queryParameters,
    T Function(dynamic)? fromJson,
  }) async {
    final response = await _dio.get(path, queryParameters: queryParameters);
    return fromJson != null ? fromJson(response.data) : response.data;
  }

  Future<T> post<T>(
    String path, {
    dynamic data,
    T Function(dynamic)? fromJson,
  }) async {
    final response = await _dio.post(path, data: data);
    return fromJson != null ? fromJson(response.data) : response.data;
  }
}

class _AuthInterceptor extends Interceptor {
  final Ref _ref;

  _AuthInterceptor(this._ref);

  @override
  void onRequest(RequestOptions options, RequestInterceptorHandler handler) {
    final token = _ref.read(authProvider).accessToken;
    if (token != null) {
      options.headers['Authorization'] = 'Bearer $token';
    }
    handler.next(options);
  }

  @override
  void onError(DioException err, ErrorInterceptorHandler handler) async {
    if (err.response?.statusCode == 401) {
      await _ref.read(authProvider.notifier).refreshToken();
      final newToken = _ref.read(authProvider).accessToken;
      if (newToken != null) {
        err.requestOptions.headers['Authorization'] = 'Bearer $newToken';
        final response = await Dio().fetch(err.requestOptions);
        handler.resolve(response);
        return;
      }
    }
    handler.next(err);
  }
}

Why Flutter May Be Better for SaaS in 2025

• Cross-platform UI consistency – Single codebase renders identically on all platforms
• Web, mobile, and desktop from day one – True multi-platform deployment
• Faster animations and performance – Skia rendering engine bypasses platform UI
• First-class Firebase integration – Real-time data, auth, and analytics built-in
• Type safety throughout – Dart catches errors at compile time
• More control over UI – Build polished design systems for B2B apps

When to Choose React Native Instead

• You have an existing React/JavaScript team
• You plan to heavily use npm packages or web-based libraries
• You only need mobile (iOS/Android), not desktop/web
• You want faster onboarding for devs familiar with web tech
• You need native look and feel rather than custom UI

Common Mistakes to Avoid

1. Choosing based on language familiarity alone

JavaScript experience doesn’t automatically make React Native the better choice. Consider your app’s specific requirements for performance, platform coverage, and UI consistency.

2. Underestimating platform differences in React Native

React Native uses native components, which means subtle UI differences between iOS and Android. Budget time for platform-specific testing and fixes.

3. Over-engineering state management

Start simple. Provider or basic Riverpod for Flutter, Context or Zustand for React Native. Add complexity only when needed.

4. Ignoring app size and startup time

Flutter apps tend to be larger initially. Use deferred loading, tree shaking, and optimize assets. React Native apps may have slower JavaScript initialization.

5. Not planning for offline support

SaaS apps need offline capabilities. Both frameworks support local storage, but plan your sync strategy early.

Real-World SaaS Use Cases

Related

• React Native Libraries You Should Know in 2025
• Flutter State Management: Provider vs Riverpod
• Flutter + Serverpod vs React Native + Express

Final Verdict: Which One Wins for SaaS?

In 2025, Flutter edges ahead for full-featured, cross-platform SaaS products due to its superior UI consistency, native performance, and ability to deploy across mobile, web, and desktop from a single codebase. The Dart ecosystem has matured significantly, and tools like Riverpod provide excellent state management solutions.

However, React Native still excels for mobile-first MVPs and teams with existing React expertise. The npm ecosystem provides instant access to thousands of packages, and the familiar JSX syntax reduces onboarding time for web developers.

The right choice depends on your specific needs: If you need true cross-platform coverage including desktop and web with pixel-perfect UI, choose Flutter. If you’re building a mobile-focused product with an existing JavaScript team, React Native remains an excellent choice.