Switching React Native to Hermes: What Actually Changes at Build Time
Hermes can shrink your React Native JS bundle and speed startup, but it changes debugging and may break native modules. Verify before you ship.
Loading…
ReadMeFeed / Community knowledge
Reactnative
Real questions. Useful conversations. Find the people who know your stack.
Reactnative
Frameworks & web · #reactnative
androidTuning FlatList Virtualization Props to Cut Jank on Mid-Range Android Devices
Large React Native lists drop frames on mid‑range Android because FlatList renders more rows than the JS thread can handle. Tuning props like initialNumToRender, windowSize, and maxToRenderPerBatch smooths scrolling but raises blank‑cell risk.
Choosing Hermes in React Native: Startup Gains, Build Costs, and Compatibility Checks
Hermes compiles JavaScript to bytecode ahead of time, cutting React Native startup and memory. Here is how to enable it, verify it is active, and know when it will break your app.
Why FlatList Beats ScrollView for Long Lists in React Native
ScrollView with .map() mounts every item instantly — killing performance on long lists. FlatList virtualizes, recycles, and stays fast. Here's the practical prop configuration that makes it work, a 5,000-row before/after example, and the trade-offs you'll hit with dynamic heights or FlashList.
Your React Native Feed Doesn't Need Every Row Rendered: FlatList Windowing Done Right
ScrollView renders every row eagerly; FlatList renders only what's near the viewport. Here's how to tune windowing, guard onEndReached pagination, and use getItemLayout for free performance.
Adopting the Hermes JavaScript Engine in React Native: Architecture Note
Learn how to add the Hermes JavaScript engine to a React Native app: minimal config steps, trust boundaries, verification methods, and when to reconsider the choice.
React Native's New Architecture: What Actually Changes When You Turn It On
React Native's New Architecture replaces the JSON bridge with direct synchronous native calls. Here's what Fabric, TurboModules, and bridgeless mode actually change, plus a safe migration order.
Enabling Hermes in React Native for Faster Startup and Lower Memory
Learn how to enable the Hermes JavaScript engine in a React Native project to improve startup time and reduce memory usage, with steps for Android and iOS, verification commands, and rollback instructions.
Diagnose & Fix Janky FlatList Rendering in React Native
A step‑by‑step diagnostic guide to identify and fix janky FlatList rendering in React Native. Learn how to spot symptoms, audit keyExtractor and renderItem, tune windowing props, add getItemLayout, and when to move to FlashList.