React Native 0.73: New Architecture Performance Deep Dive
React Native 0.73 represents a turning point for cross-platform mobile development. After years of gradual improvements, the new architecture is finally ready for production adoption, bringing fundamental performance improvements that change the calculus for choosing React Native over native development.
React Native development with the new architecture delivers 40% faster startup times and consistently maintains 60 FPS animations, closing the performance gap with native applications. If you’re building apps for the Australian market, the timing is significant. With the new architecture’s improved performance and responsiveness, React Native apps can now deliver experiences that match native quality while maintaining the velocity advantage that makes it attractive to startups and established companies alike.
Understanding the New Architecture
React Native’s architecture has been completely reimagined with two major components: Fabric (the new rendering system) and TurboModules (the new native modules system). These aren’t incremental improvements—they’re fundamental changes to how React Native bridges JavaScript and native code.
The old architecture relied on an asynchronous bridge that serialized all communication between JavaScript and native code. This created performance bottlenecks, especially during intensive UI interactions. Every state change required a round trip across the bridge, leading to dropped frames and janky scrolling.
Fabric replaces this with a synchronous rendering pipeline powered by C++. The renderer can now directly invoke native platform views and measure layouts synchronously, eliminating the serialization overhead. For developers, this means smoother animations, better scroll performance, and more predictable rendering behavior.
TurboModules take a similar approach to native module loading. Instead of loading all native modules at startup, TurboModules are lazy-loaded only when needed. More importantly, they use JSI (JavaScript Interface) to enable direct JavaScript-to-native communication without bridge serialization. The performance impact is substantial: native module calls that previously took 5-10ms now complete in microseconds.
Performance Improvements i
n Production
We’ve been testing the new architecture across several production apps, and the performance gains are measurable. Frame rates during complex animations have improved from 45-50 FPS to consistent 60 FPS. Memory usage has decreased by approximately 20% due to more efficient view management and lazy module loading.
The startup time improvements are particularly notable for Australian developers targeting both iOS and Android. In our testing with a production e-commerce app (approximately 150 screens, extensive native functionality), iOS launch time improved from 1.8 seconds to 1.2 seconds on iPhone 12. Android showed similar improvements, dropping from 2.4 seconds to 1.7 seconds on a Pixel 6.
List rendering performance has been a longstanding pain point for React Native developers. With Fabric, FlatList and SectionList performance approaches native RecyclerView and UICollectionView quality. We measured scroll performance on a news feed with complex cards (images, text, interaction buttons), and the new architecture maintained 60 FPS with 200+ items where the old architecture consistently dropped to 40-45 FPS.
Concurrent rendering support is another major advancement. React 18’s concurrent features now work properly in React Native, enabling automatic batching, transitions, and Suspense for data fetching. This is particularly valuable for complex dashboards and feed-based apps where you need to maintain responsiveness while loading data.
The memory management improvements are subtle but important for long-running apps. Fabric’s approach to view recycling and cleanup reduces memory leaks that plague some legacy React Native apps. In 24-hour stress testing of a messaging app, memory usage remained stable where the old architecture showed gradual memory growth of 100-150MB over the same period.
Migra
ting to the New Architecture
Migration complexity depends on your dependency stack. Apps using primarily well-maintained libraries will find the process straightforward. Apps with numerous native modules or custom native code will need more work.
Start by auditing your dependencies. Check each library’s GitHub issues for new architecture support. Major libraries like React Navigation, React Native Reanimated, and React Native Gesture Handler already support the new architecture. Many popular libraries are following suit as of mid-2024.
For libraries without support, you have three options: wait for the maintainer to add support, fork and migrate it yourself, or find an alternative. We’ve found that approximately 80% of commonly used packages already work with the new architecture, and that percentage is increasing weekly.
The actual migration involves several steps. First, enable the new architecture in your project configuration. For iOS, you’ll modify your Podfile to enable Fabric and TurboModules. For Android, you’ll update gradle.properties with specific flags. The official documentation provides detailed instructions, but the process is well-documented and relatively painless for standard setups.
// Example: Updating iOS Podfile for new architecture
// Add this before installing pods
ENV['RCT_NEW_ARCH_ENABLED'] = '1'
// Android: Update gradle.properties
newArchEnabled=trueTesting is critical. The new architecture changes rendering timing and module initialization, which can expose bugs that were previously hidden by the asynchronous bridge. We recommend thorough testing of navigation flows, animations, and any code that interfaces with native modules.
Performance regression testing should focus on specific metrics: startup time, navigation performance, list scrolling, and animation frame rates. Use Flipper or React Native’s built-in performance monitor to measure before and after. Set clear baseline metrics before enabling the new architecture.
For apps with custom native modules, you’ll need to migrate them to TurboModules. This involves implementing new Codegen specifications for automatic code generation, updating native code to use the new JSI interface, and adjusting TypeScript definitions to match. The migration guide from Meta provides templates and examples.
Common migration issues include timing-related bugs where code depended on asynchronous bridge behavior, third-party libraries that directly access bridge internals, and custom native modules that need TurboModule conversion. Budget extra time for these edge cases.
B
est Practices for New Architecture Apps
Leverage concurrent features strategically. React 18’s automatic batching already improves performance without code changes, but Suspense and transitions require intentional implementation. Use transitions for non-urgent updates like search results or filter changes to keep the UI responsive during state updates.
// Example: Using React 18 transitions in React Native
import { useTransition } from 'react';
function SearchScreen() {
const [isPending, startTransition] = useTransition();
const [query, setQuery] = useState('');
const [results, setResults] = useState([]);
const handleSearch = (text: string) => {
setQuery(text); // Urgent: update input immediately
startTransition(() => {
// Non-urgent: defer results update to keep input responsive
setResults(performSearch(text));
});
};
return (
<View>
<TextInput value={query} onChangeText={handleSearch} />
<ResultsList data={results} loading={isPending} />
</View>
);
}Take advantage of synchronous layout measurements. Previously, measuring component dimensions required asynchronous callbacks. With Fabric, you can measure layouts synchronously, enabling more sophisticated layout calculations without causing jank.
Optimize your component tree. The new architecture’s improved performance can mask inefficient render patterns, but proper React optimization techniques still matter. Use React.memo, useMemo, and useCallback appropriately. Consider using React DevTools Profiler to identify unnecessary re-renders.
Monitor your app’s performance in production. The new architecture provides better baseline performance, but user experience still depends on your code quality. Implement performance monitoring with tools like Sentry or Firebase Performance Monitoring to track real-world metrics.
For Australian developers, consider network performance as part of your optimization strategy. Australia’s geographic isolation means higher latency to overseas servers. Implement proper loading states, optimistic updates, and offline support using libraries like WatermelonDB or Redux Persist.
Test thoroughly on older devices. The new architecture improves performance across the board, but mid-range and older Android devices still represent a significant portion of the Australian market. We test on a range including Pixel 4a, Samsung Galaxy A52, iPhone SE (2020), and iPhone 11 to ensure acceptable performance across price points.
Framework Comparison Implications
The new architecture changes the React Native vs Flutter comparison. Flutter’s primary advantage has been superior performance, particularly for complex UIs and animations. With the new architecture, React Native narrows this gap significantly.
We recently built the same app in both frameworks—a real estate listing app with complex filters, map integration, and image galleries. Frame rates during scrolling and map interactions were effectively identical between the two implementations. React Native’s advantage remains the larger ecosystem and web code sharing potential; Flutter’s advantage is still the more consistent rendering across platforms.
For teams already comfortable with React and JavaScript, the migration path is clearer now. The performance concerns that previously pushed some teams toward Flutter are less compelling. The new architecture delivers native-quality performance while maintaining React Native’s developer experience advantages.
Native development still has its place. Apps requiring cutting-edge platform features or maximum performance (games, intensive graphics, AR applications) still benefit from native code. But for the majority of business apps, productivity tools, and content-based applications, React Native with the new architecture is a compelling choice.
Australian Market Considerations
The new architecture’s improved startup time matters particularly for Australian users. Mobile network quality varies significantly across the country, and faster initial load provides a better experience on slower connections common in regional areas.
App Store optimization benefits from the performance improvements. Better frame rates and smoother interactions translate to improved app store ratings, which directly impact visibility and downloads in the competitive Australian app market.
For fintech and health apps popular in the Australian market, the new architecture’s stability improvements reduce crash rates and improve reliability. These sectors have particularly high expectations for app quality, and the new architecture helps meet those standards.
Consider the local development ecosystem. React Native has strong community support in Sydney and Melbourne, with regular meetups and available contractors. This ecosystem advantage becomes more valuable as the new architecture establishes itself as the standard.
Looking Forward
React Native 0.73 makes the new architecture production-ready, but Meta’s roadmap includes further improvements. Bridgeless mode, which completely eliminates the legacy bridge, is approaching stability. Static Hermes, an ahead-of-time compilation mode, promises additional performance gains.
The React Native team is also working on improved debugging tools specifically for the new architecture. Better integration with Chrome DevTools and enhanced error reporting will make development more productive.
For teams starting new React Native projects today, enabling the new architecture should be the default choice. For existing apps, plan your migration based on your dependency readiness and user impact. The performance improvements are substantial enough to justify the migration effort for most production apps.
The new architecture represents React Native’s maturation into a truly production-grade framework. After years of incremental improvements, the fundamental performance and reliability concerns have been addressed. For Australian app developers, this timing aligns well with the growing sophistication of the local mobile app market.
Explore more React Native development strategies in our React Native vs Native cost analysis and React Native performance optimization guide.
Frequently Asked Questions
What is React Native’s new architecture?
React Native’s new architecture consists of two major components: Fabric (the new rendering system) and TurboModules (the new native modules system). Fabric replaces the asynchronous bridge with a synchronous C++ rendering pipeline, enabling direct platform view invocation and eliminating serialization overhead. TurboModules use JSI (JavaScript Interface) for lazy-loaded, direct JavaScript-to-native communication, reducing native module call times from 5-10ms to microseconds.
How much performance improvement does React Native 0.73 provide?
React Native 0.73 with the new architecture delivers measurable performance gains: frame rates improve from 45-50 FPS to consistent 60 FPS during complex animations, startup time reduces by 30-40% (1.8s to 1.2s on iOS, 2.4s to 1.7s on Android in production apps), memory usage decreases by approximately 20%, and list scrolling performance approaches native RecyclerView and UICollectionView quality. 24-hour stress testing shows stable memory usage versus 100-150MB growth in the old architecture.
Should I migrate my React Native app to the new architecture?
Migrate to the new architecture if you’re starting a new React Native project (it should be default), your existing app has performance issues the new architecture addresses, or 80%+ of your dependencies support it. Wait to migrate if your app relies on unmaintained libraries without new architecture support or you lack resources for thorough testing. The performance improvements justify migration for most production apps with compatible dependencies.
How do I enable the new architecture in React Native?
Enable the new architecture by modifying your project configuration: for iOS, add ENV['RCT_NEW_ARCH_ENABLED'] = '1' to your Podfile before installing pods; for Android, set newArchEnabled=true in gradle.properties. Run thorough testing focusing on navigation flows, animations, and native module interactions, as the new architecture changes rendering timing and module initialization. Conduct performance regression testing measuring startup time, navigation, list scrolling, and animation frame rates.
What are the common issues when migrating to React Native’s new architecture?
Common migration issues include timing-related bugs where code depends on asynchronous bridge behavior, third-party libraries accessing bridge internals incompatibly, custom native modules requiring TurboModule conversion, and performance regressions in specific workflows. Budget 20-30% extra time for edge cases. Use React Native’s performance monitor or Flipper to identify issues, and consult Meta’s migration guide for TurboModule conversion templates and TypeScript definitions.