June 05, 2024

React 19: Upcoming features.

Continuing with the evolution of React, I will talk to you about the exciting new features in React 19. React just got a major update with the release of version 19. While learning the new features might take some time, the good news is that React 19 focuses more on reducing the amount of code you need to write. The main goal of these updates is to boost your React applications. To demonstrate the impact of these improvements, we will compare code snippets from React 18 and React 19. Let’s jump into it.

In this code, useCallback prevents the function from being recreated on each render. Similarly, useMemo recomputes the value only when count changes, preventing any unnecessary computation.

React 18:

React 19:

In this code, useRef creates a ref that is passed as a prop to a child component, where forwardRef is used.

React 18:

React 19:

In this code, useEffect fetches data from an API, stores the data in a piece of state, and displays it on the UI after handling loading and error cases.

React 18:

React 19:

All these features are thanks to the compiler. What does it do? The React compiler converts your React code into regular JavaScript. Its main purpose is to improve your app’s performance without you having to think about it. The total number of characters in the code examples for React 18.2.0 is 582, while the code for React 19 totals 476. That is a reduction of approximately 18% in the amount of code. Can you imagine having a React app with 50,000 characters of code? Thanks to the new features and the React compiler in React 19, this app could be written with only 41,000 characters. That is a difference of 9,000 characters. It is not just about saving characters or reducing typing time; it also saves developers time spent on optimizing the app’s performance and figuring out how and where to use these performance hooks.

And that is all for today, folks. I hope you found this overview of React 19 new features insightful. If you are curious about how these updates can simplify your developer’s experience, I encourage you to explore React 19 and its capabilities. You will not be disappointed.

If you like to learn more about React, please take a look at the following links: