New in React 18

What’s New in React 18: The Latest Version Explained

React, developed by Meta (formerly Facebook), is one of the most popular JavaScript libraries for building user interfaces. With the release of React 18, developers now have access to powerful new features designed to improve performance and user experience, especially in concurrent scenarios.

In this article, we’ll explore everything you need to know about React 18—its key features, improvements, and how to get started.

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Overview of React 18

• Release Date: March 29, 2022

• Current Stable Version: React 18.2.0
  (Always check the official React docs for the most up-to-date version.)

React 18 introduces concurrent rendering, a new default rendering behavior that helps make apps more responsive by rendering UI in the background without blocking user interactions.

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Key Features and Updates

1. Concurrent Rendering with createRoot

React 18 replaces the old ReactDOM.render with the new createRoot API to enable concurrent features:

import { createRoot } from 'react-dom/client';

const container = document.getElementById('root');
const root = createRoot(container);
root.render(<App />);

Why it matters:

• Enables React to work on multiple tasks at once

• Improves perceived performance

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2. Automatic Batching

React 18 can now automatically batch multiple state updates—even in asynchronous code like setTimeout, Promise, or native event handlers.

setTimeout(() => {
  setCount(c => c + 1);
  setVisible(v => !v);
  // React will batch these updates into a single re-render
}, 1000);

Benefits:

• Fewer renders

• More efficient updates

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3. Enhanced Suspense

React 18 improves <Suspense> for better integration with concurrent features and data fetching libraries.

<Suspense fallback={<Spinner />}>
  <UserDashboard />
</Suspense>

Use cases:

• Lazy-loading components

• Loading data with libraries like Relay or React Query

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4. useTransition and startTransition

These new hooks help prioritize urgent vs. non-urgent updates. Ideal for UI-heavy tasks like search filters or tab switching.

const [isPending, startTransition] = useTransition();

startTransition(() => {
  setQuery(input);
});

When to use it:

• Autocomplete

• Complex filtering

• Content navigation

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5. useId Hook

A simple way to generate unique, consistent IDs for accessibility and server-side rendering.

const id = useId();
return <label htmlFor={id}><input id={id} /></label>;

No more worrying about unique IDs in SSR!

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How to Upgrade to React 18

1. Install the latest version:

npm install react@18 react-dom@18

2. Update root rendering:

import { createRoot } from 'react-dom/client';

const container = document.getElementById('root');
const root = createRoot(container);
root.render(<App />);

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Additional Resources

• React 18 Official Docs: https://reactjs.org/docs

• React 18 Release Blog: https://reactjs.org/blog/2022/03/29/react-v18.html

• GitHub Discussions: https://github.com/reactwg/react-18/discussions

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Final Thoughts

React 18 is a big step toward making React apps faster, smoother, and more responsive. With features like concurrent rendering, automatic batching, and transitions, it gives developers more control over performance without increasing complexity.

If you're starting a new React project, using React 18 is a no-brainer. And if you're upgrading an existing app, the transition is smooth—most changes are opt-in.

Ready to build better interfaces? Start exploring React 18 today!