React 19: What's New

React 19 brings groundbreaking changes to how we build user interfaces. Here's what you need to know.

Key Features

React Server Components

Server Components allow rendering components on the server, reducing bundle size and improving performance.

Actions

The new Actions API simplifies form handling:

function SearchForm() {
  const search = async (formData) => {
    'use server';
    const query = formData.get('query');
    return await searchResults(query);
  };
  return <form action={search}>...</form>;
}

New Hooks

use() — Read resources directly in render
useOptimistic() — Optimistic updates made simple

Migration Strategy

Start with React 18.x and fix all deprecation warnings
Upgrade to React 19 beta
Test thoroughly with strict mode
Replace deprecated lifecycle methods

Conclusion

React 19 represents a significant step forward for the ecosystem. The new server components paradigm changes how we think about React applications.

React 19: What's New and How to Migrate