React 19: Here's What You Need to Know

React 19 is on the horizon, bringing many new features designed to streamline web development and enhance performance.

Usually the updates add some small things, but this update is more than just an upgrade; I think it's a game-changer for developers using React.js.

The TLDR;

• Much more serverside React.js
• An awesome new compiler

But here's a little more detail on the big additions:

React Compiler

At the heart of React 19 is the introduction of the React Compiler. This tool transforms React code into standard JavaScript, aiming to double efficiency.

It addresses the challenge of unnecessary re-renders by automating optimization. This means no more fighting with useMemo, useCallback, and memo. You'll now have efficient code by default!

Plans are in place to open-source the React Compiler, expanding its accessibility and potential for community-driven enhancements.

But just by using the React Compiler, you should have faster applications.

Actions

React 19 makes it easier to handle data within applications by introducing Actions. Actions will allow us to connect functions to DOM elements such as <form/>.

The action function can operate synchronously or asynchronously. You can define them on the client side using standard JavaScript or on the server with the 'use server' directive.

And while using the actions you'll be able to use hooks like useFormStatus, and useFormState to access the current state and response of the form action.

I've been testing them out in Next.js, and once I got my head around the patterns they have been absolutely fantastic additions. It'll be the default way I create forms now.

Server Components

Server Components are your components rendered on the server (yes, you can call me Captain Obvious). This is awesome because it usually results in faster load times for new visitors and improved SEO. It also streamlines data fetching too!

Asset Loading

Suspense is being used for the asset-loading process, covering elements like stylesheets, fonts, and scripts. This integration allows React to efficiently judge when these components are ready to be displayed.

Document Metadata

You'll easily update everything you need without relying on another library. And less dependencies is always good!

In React 19, you'll get built-in support for rendering <title>, <meta>, and metadata <link> tags anywhere in your component tree.

React 19 promises to be an exciting update for the developer community, and I can't wait to start building my apps with it!