Vinicius Gularte
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Exploring React's Concurrent Mode and Suspense


Exploring React's Concurrent Mode and Suspense

React has always been at the forefront of frontend development, introducing innovative features that enhance both developer experience and user interaction. Two such groundbreaking features are the Concurrent Mode and Suspense. In this post, we'll delve deep into these features, understanding their significance and how they can be leveraged in React applications.

What is Concurrent Mode?

Concurrent Mode is a set of new features that help React apps stay responsive and gracefully adjust to the user's device capabilities and network speed. It allows React to break the rendering process into smaller chunks, working on multiple tasks simultaneously without blocking the main thread.


  1. Improved User Experience: By preventing the UI from becoming unresponsive, users get a smoother experience, especially during heavy computations or data fetching.
  2. Enhanced Priority: React can prioritize updates based on their importance. For instance, it can interrupt an ongoing render to immediately handle a user's input.

Introducing Suspense

While Concurrent Mode focuses on rendering, Suspense concentrates on data fetching. Suspense allows components to “wait” for something before rendering, offering a seamless user experience during data fetching, code splitting, or any asynchronous operations.

How does it work?

With Suspense, you can wrap a component tree with a <Suspense> boundary, specifying a fallback UI to display while waiting for some asynchronous operation to complete.

import React, { Suspense } from 'react'
function App() {
return (
<Suspense fallback={<div>Loading...</div>}>
<ProfileData />

In the example above, the ProfileData component might fetch user data. Until the data is fetched, the "Loading..." message will be displayed.

Combining Concurrent Mode with Suspense

When used together, Concurrent Mode and Suspense offer a powerful combination to handle both rendering and data fetching seamlessly.

In a typical React application, once data fetching begins, the user might experience a loading state until the data is ready. With Suspense, you can provide a fallback UI, ensuring that users aren't left staring at a blank screen or a spinning loader for too long.


React's Concurrent Mode and Suspense are game-changers in the world of frontend development. By understanding and effectively implementing these features, developers can significantly enhance user experience, making applications feel faster and more responsive. As React continues to evolve, embracing these advanced features will be crucial for any developer aiming to build cutting-edge web applications.