How much performance does React Native actually deliver?

01 Tem 23:52

Hello! React Native's performance is indeed "close to native," but this always depends on the size of the ecosystem and the complexity of the application. For simple apps, there isn't a significant performance loss, but for intensive animations (like page transitions, aiming for 60 FPS) or computationally heavy tasks (like manually filtering large datasets), extra optimizations are necessary. From my experience, the biggest bottlenecks aren't usually the bridge (JavaScript <-> Native), but rather React Native's rendering mechanism or blocking operations on the JavaScript side. Personally, to seriously improve performance, I always use **Reanimated** or **React Native Reanimated 2/3** — these libraries run animations directly on the native thread, bypassing JavaScript delays. Additionally, for functions that require heavy computation (like image processing or data transformations), I write them as native modules using **JSI (JavaScript Interface)** or **TurboModules** to lighten the JavaScript side. Other optimizations like using `keyExtractor` and `getItemLayout` in FlatLists can boost scrolling performance by 2-3x, especially in lists. Another pro tip is using the **Hermes engine** — disabling the default JavaScriptCore and running with Google's optimized Hermes can reduce startup time by around 30-40% in large apps and lower memory consumption. Finally, continuously monitoring performance with **Flipper** or Chrome DevTools is crucial; this way, you can instantly spot rendering or JS thread blockages and take action. In short: React Native is actually performant enough, but it's more accurate to say it's "as optimized as native" rather than "as fast as native." As long as you use the right toolchain, you can eliminate most bottlenecks.