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Improving performance in a React application is essential for providing a smooth and fast user experience. As your app grows, even small inefficiencies can add up and degrade performance. In this blog post, we’ll cover some practical strategies to make your React apps faster and more efficient.

1. Use react.memo to avoid unnecessary re-renders

When components re-render too often or without need, it can affect performance. Use React.memo to memoize functional components:

const ExpensiveComponent = React.memo(function ExpensiveComponent({ data }) {
  // This will only re-render if `data` changes
  return <div>{data.value}</div>;
});

This is particularly helpful when you pass down props that don’t change often.

2. Memoize expensive calculations with usememo

Avoid re-computing values unless dependencies change:

const filteredItems = useMemo(() => {
  return items.filter(item => item.active);
}, [items]);

This ensures filteredItems is only recalculated when items changes.

3. Use usecallback for stable function references

Passing new function references to child components can trigger unnecessary re-renders. Wrap callbacks with useCallback:

const handleClick = useCallback(() => {
  doSomething();
}, []);

This ensures that handleClick has a stable identity across renders.

4. Lazy load components with react.lazy and suspense

Split your app into smaller chunks and load components only when needed:

const HeavyComponent = React.lazy(() => import('./HeavyComponent'));

function App() {
  return (
    <Suspense fallback={<div>Loading...</div>}>
      <HeavyComponent />
    </Suspense>
  );
}

This reduces initial load time and speeds up perceived performance.

5. Avoid anonymous functions in JSX

This might seem minor, but using anonymous functions in render can lead to re-renders and make debugging harder:

// ❌ Not recommended
<button onClick={() => doSomething()}>Click</button>

// ✅ Better
const handleClick = () => doSomething();
<button onClick={handleClick}>Click</button>

6. Virtualize long lists

Rendering large lists can be costly. Use libraries like react-window or react-virtualized to render only what’s visible:

import { FixedSizeList as List } from 'react-window';

<Listheight={400}
  itemCount={1000}
  itemSize={35}
  width={300}
>
  {({ index, style }) => (
    <div style={style}>Row {index}</div>
  )}
</List>

7. Use production build

Always use the production version of React in deployment. It’s faster and smaller:

npm run build

Serve the /build folder to your users, not the development version.

8. Avoid deep prop drilling

Deeply nested props can make your app slower and harder to maintain. Use context wisely or adopt state management tools like Redux, Zustand, or Jotai to keep your component tree lean.

9. Profile your application

Use the React DevTools profiler to identify slow components and unnecessary renders:

Install React Developer Tools extension
Use the “Profiler” tab to record interactions
Look for expensive components or unnecessary renders

Conclusion

React gives you powerful tools out of the box, but performance tuning still requires careful coding practices. From memoization to lazy loading, these optimizations help keep your app fast and responsive. Start with profiling, apply what’s needed, and remember: not all optimizations are worth it—prioritize based on impact.

How to optimize the performance of a react application