How to Optimize React Native Performance for Faster Apps

Fernando Chaves

August 13, 2025

React Native is one of the most popular frameworks for building cross-platform mobile apps, but without proper optimization, even the best apps can feel slow and unresponsive. Performance directly affects user retention, engagement, and app store ratings. In this guide, we will go step-by-step through five proven techniques to optimize React Native performance so your app loads faster, runs smoother, and keeps users coming back. These methods are based on real-world experience and updated with the latest React Native improvements in 2025.

1. Use Virtualized Lists for Large Data Sets

When building list-based screens, using ScrollView is one of the fastest ways to kill performance. It renders every single element at once, increasing memory usage and slowing down rendering. Instead, switch to FlatList or SectionList, which only render visible items and recycle views as the user scrolls. This drastically reduces memory usage and keeps the UI smooth even with hundreds of items.
For best results, set a keyExtractor, use getItemLayout for fixed-size rows, and enable initialNumToRender thoughtfully to avoid blank screens. For extremely large lists, libraries like FlashList can outperform the default FlatList by using more efficient virtualization techniques.

<FlatList
  data={items}
  keyExtractor={item => item.id}
  getItemLayout={(_, index) => ({
    length: ITEM_HEIGHT,
    offset: ITEM_HEIGHT * index,
    index,
  })}
  renderItem={({item}) => <ItemComponent {...item} />}
/>

2. Optimize Images and Other Static Assets

Images are one of the heaviest assets in any mobile app, and poor optimization can significantly impact both load time and scrolling performance. Use compressed formats like WebP instead of PNG or JPEG wherever possible. For icons and illustrations, SVGs are lightweight and scale perfectly. Implement caching to prevent unnecessary network calls—react-native-fast-image is a great library for this. Avoid loading high-resolution images on low-resolution displays and consider lazy-loading offscreen images to save memory.

<FastImage
  style={{width: 200, height: 200}}
  source={{
    uri: imageUri,
    priority: FastImage.priority.normal,
    cache: FastImage.cacheControl.cacheOnly,
  }}
/>

3. Enable Hermes and Adopt the New Architecture

One of the most effective React Native performance optimizations is enabling the Hermes JavaScript engine. Hermes improves app startup times, reduces memory consumption, and can shrink your JavaScript bundle size. To enable Hermes, update your android/app/build.gradle file. In 2025, pairing Hermes with the New Architecture (Fabric, TurboModules, and JSI) can result in major speed improvements by reducing the overhead between JavaScript and native code. Additionally, enabling the React Compiler can automatically optimize your components for faster rendering.

project.ext.react = [
  enableHermes: true
]

4. Minimize Unnecessary Component Re-renders

Excessive re-renders can cause UI lag and higher CPU usage. The first step is to identify unnecessary updates using tools like why-did-you-render or React’s built-in Profiler. Then, apply optimizations such as wrapping components with React.memo or extending PureComponent for class components. Use useCallback and useMemo to avoid creating new function and object references on each render. Whenever possible, store non-UI state in useRef to prevent triggering re-renders altogether.

const MyButton = React.memo(({onPress, label}) => (
  <Button onPress={onPress} title={label} />
));

const Parent = () => {
  const handlePress = useCallback(() => { /* action */ }, []);
  return <MyButton onPress={handlePress} label="Click me" />;
};

5. Profile and Monitor Performance Regularly

Optimization is not a one-time task—it’s an ongoing process. Use Flipper with the React Native Performance Plugin to monitor frame rates, CPU usage, and memory consumption in real time. On iOS, use Instruments, and on Android, use Android Studio Profiler. Check for any components that block the JS thread, remove unused dependencies, and strip out console.log calls in production with babel-plugin-transform-remove-console. Regular profiling ensures your app stays fast as it grows.

npm install --save-dev babel-plugin-transform-remove-console

Conclusion

By applying these five React Native optimization techniques—using virtualized lists, optimizing assets, enabling Hermes and the new architecture, minimizing re-renders, and monitoring performance—you can dramatically improve load times, reduce lag, and deliver a smooth user experience. Every millisecond counts, and these changes will not only make your app faster but also improve your app store ratings and user retention.

If you want to skip months of setup and start building high-performance apps immediately, check out my React Native Boilerplate. It’s already configured with authentication, internationalization, payments, and AI integration, making it the perfect starting point for mobile developers who want to ship apps faster without sacrificing performance.