React 19

This repository is a playground for React 19. Feel free to use it to test new features and functionalities.

Note: This repository is not meant to be used in production.

Note: I choose to use nextjs to test React 19 features since some features need a React framework to work.

How to use

1. Clone the repository
2. Install the dependencies
3. Run the project:

npm run dev

React Compiler

React 19 introduces a new experimental compiler that automatically memoizes your code. This greatly reduces the need to use useMemo, useCallback, and React.memo.

To test the new compiler in your Next.js 15 RC project, you need to add the following configuration to your next.config.js file:

const nextConfig = {
  experimental: {
    reactCompiler: true,
  },
}

export default nextConfig

Note: Check the Next.js documentation for updated information on how to use the React Compiler in Next.js. The above configuration may change in the future since we are using a beta version of Next.js (Next.js 15 RC) at the time of writing this document

Resources

• React 19
• React 19 on Medium
• React Compiler
• Next.js

License

• MIT