Apps7 min readMarch 10, 2026

10 React Native Performance Tips You're Probably Ignoring

Your React Native app is slow and you know it. Here are the concrete fixes that actually move the needle on Hermes, FlatList, and JS thread.

Sneha Patel

Mobile developer building cross-platform apps since 2018.

The Performance Problem

React Native apps feel sluggish when developers treat it like React on the web.

1. Use Hermes Engine

json
project.ext.react = [enableHermes: true]

2. Optimize FlatList

tsx
<FlatList
  data={items}
  renderItem={renderItem}
  keyExtractor={item => item.id}
  getItemLayout={(_, index) => ({
    length: ITEM_HEIGHT,
    offset: ITEM_HEIGHT * index,
    index,
  })}
  removeClippedSubviews={true}
  maxToRenderPerBatch={10}
/>

3. Memoize Everything

tsx
const renderItem = useCallback(({ item }) => (
  <PostCard post={item} />
), []);

Conclusion

Performance is about reducing JS thread work and maximizing native offloading.

#React Native #Performance #Mobile #JavaScript