React Native 0.82 - A New Era

🚀 Major Highlights

• New Architecture Only: React Native 0.82 fully drops support for the Legacy Architecture. Even if you try to disable the New Architecture via flags, it will be ignored. This marks a major milestone in React Native’s modernization journey.

• Hermes V1 (Experimental): A new version of the Hermes JavaScript engine is available for opt-in. It brings performance improvements in bundle load time and Time to Interactive (TTI), especially on low-end Android devices.

• React 19.1.1: Ships with the latest React version, which now fully supports owner stacks and improves behavior of useDeferredValue and startTransition in Suspense boundaries.

• DOM Node APIs: Native components now expose DOM-like APIs via refs (e.g., parentNode, getBoundingClientRect()), making it easier to traverse and measure UI trees — aligning React Native closer to web development patterns.

🧪 Developer Experience Improvements

• Web Performance APIs (Canary): Partial support for performance.now(), PerformanceObserver, and other web performance APIs — visible in future versions of React Native DevTools.

• Optimized Debug Build (Android): New debugOptimized build type offers near-release performance while retaining JavaScript debugging. Backported to 0.81 and Expo SDK 54.

⚠️ Breaking Changes

• Uncaught Promise Rejections: Now logged via console.error, which may surface previously hidden bugs.

• Appearance API: setColorScheme() no longer accepts null; use 'unspecified' instead.

• Gradle 9.0.0: Android build system updated — minimal impact expected.

• C++ Header Cleanup: Deprecated includes removed; use updated paths.

📦 Migration Tips

• Migrate to 0.81 or Expo SDK 54 first to enable New Architecture safely.

• Then upgrade to 0.82, which enforces it.

• Interop layers remain for now, so most 3rd-party libraries will still work.