Flutter vs React Native: which is right for your startup app?

If you are planning a startup app, an early question is whether to use Flutter, React Native or fully native code. Flutter and React Native both let one team build iPhone and Android apps from a single codebase, which is why they are common choices for a first version. They work in different ways, and those differences affect hiring, design and access to device features. This guide explains the practical differences, based on each project's own documentation.

What are Flutter and React Native?

Flutter is an open source, cross-platform UI toolkit. Apps are written in Dart, a language that dart.dev describes as client-optimized for building fast apps on any platform. According to Flutter's architectural overview, apps run in a virtual machine with stateful hot reload during development, and for release they are compiled directly to machine code (or to JavaScript or WebAssembly for the web).

React Native is an open source framework for building Android and iOS apps with React, developed by the React Native team at Meta. You write the app in JavaScript, and the React Native documentation says new projects target TypeScript by default. React Native ships with Hermes, an open source JavaScript engine optimized for React Native that is used by default.

How does each one draw the screen?

• Flutter draws every pixel itself. Its documentation says Flutter bypasses the system UI widget libraries in favor of its own widget set, and the code that paints the interface is compiled to native code and rendered with Impeller, a rendering engine shipped inside your app. Flutter includes Material and Cupertino (iOS-style) widget sets, or you can build your own design system.
• React Native uses native views. Its documentation explains that at runtime React Native creates the corresponding Android and iOS views for your components, so a React Native button is backed by the platform's own view.

In practice, Flutter makes a pixel-identical design on every device easier, because one engine draws everything. React Native apps pick up platform conventions more naturally, because they use the platform's own components. Choose based on whether your brand needs one consistent look or an app that feels at home on each platform.

Which one performs better?

For most startup apps, both are fast enough, and code quality matters more than the framework. Each project tackles performance differently:

• Flutter's documentation argues that frameworks which sit on top of native UI libraries add overhead, and that Flutter minimizes those abstractions by painting its own widgets in compiled code.
• React Native's New Architecture, enabled by default since version 0.76, replaces the old asynchronous bridge between JavaScript and native code with the JavaScript Interface (JSI), which lets JavaScript call native methods without serialization costs. The documentation also notes that enabling it may not immediately improve every app's performance.

If your app does heavy real-time work, such as camera processing or complex animation, prototype that one feature before committing.

Is it easier to hire Flutter or React Native developers?

Rather than rely on survey numbers, look at the skills your team already has:

• React Native's documentation says it allows developers who know React to create native apps, so a startup with a React web app can share people between web and mobile.
• Flutter uses Dart, so you will usually hire Flutter developers specifically. In return, the whole app is in one language and one toolkit.

Either way, ask candidates for apps that are live in the App Store and Google Play.

How do they access native device features?

Both frameworks have packages for common features such as the camera, location and notifications, and both let developers write native code when no package exists.

• Flutter uses platform channels to send messages between Dart and native code written in Kotlin or Swift, and the dart:ffi library to call C-based APIs directly. For complex native controls such as maps, it can embed platform views, which Flutter's documentation notes carry some performance overhead.
• React Native uses Turbo Native Modules. You describe the interface in TypeScript or Flow, and a tool called Codegen generates the platform-specific code that your Kotlin, Java, Swift or Objective-C implementation plugs into.

Both can also be added to an existing native app one screen at a time: Flutter calls this add-to-app, and React Native documents integration with existing apps.

What about web and desktop?

Flutter officially supports Android, iOS, web, Windows, macOS and Linux, according to its supported platforms page. Its web FAQ is candid that Flutter suits app-like experiences such as single page apps and progressive web apps, but is not suitable for static, text-rich websites, and that its output does not align with what search engines need to index. Flutter recommends building your marketing pages in standard HTML.

React Native targets Android and iOS. Other platforms, including macOS, Windows and the web (through React Native Web), are maintained by partners and the community as out-of-tree platforms. The React Native team recommends starting new apps with a framework such as Expo, whose platform support includes Android, iOS, TV and web.

When is native Swift or Kotlin the better choice?

Native development means separate apps: Swift, usually with SwiftUI, for Apple platforms, and Kotlin, usually with Jetpack Compose, for Android. Google describes Android development as Kotlin-first and recommends Jetpack Compose for native UI, and Apple positions SwiftUI as one set of tools and APIs across all Apple devices. Native is often the better fit when:

• your app depends on new platform features as soon as they are released;
• you are building for one platform only, for example an iPhone-first consumer product;
• the app does demanding graphics, audio or background processing;
• you already have experienced iOS and Android developers on staff.

The trade-off is two codebases and usually a larger team.

How should a startup choose for its MVP?

An MVP exists to test whether people want your product, so choose the option that gets a reliable app to users with the team you can realistically hire:

• Choose React Native if you already have React or TypeScript developers, or a React web app you want to share logic and people with.
• Choose Flutter if you want one tightly controlled design across iOS and Android, or you plan to reach desktop as well as mobile from the same code.
• Choose native if you are building for one platform only, or your core feature depends on deep platform integration.

Before development starts, list the few features the MVP must have, the device features each needs, and check that a maintained package exists for each. Agree who owns the code and the App Store and Google Play accounts. Our guide to what affects mobile app development timelines covers the planning side in more detail.

If you would like a second opinion on your choice, see our mobile app development services or our page on mobile app development for US businesses.

Sources

• Flutter: Flutter architectural overview
• Flutter: Supported deployment platforms
• Flutter: Web FAQ
• Flutter: Add Flutter to an existing app
• Dart: Dart overview
• React Native: Core Components and Native Components
• React Native: About the New Architecture
• React Native: Turbo Native Modules
• React Native: Using TypeScript
• React Native: Using Hermes
• React Native: Get Started with React Native
• React Native: Out-of-Tree Platforms
• React Native: Integration with Existing Apps
• Apple Developer: SwiftUI
• Android Developers: Android's Kotlin-first approach
• Android Developers: Jetpack Compose