YouTube video: https://youtu.be/81uAxzeyL2I?si=RVuCmoWZ7gDJfBi4

This document distills key ideas, examples, and practical insights from a detailed course on React 19, focusing on new React APIs, patterns, and ecosystem improvements. It is designed to help React developers—from intermediate to advanced—understand and leverage React 19’s enhancements effectively.

Contents

1. Introduction to React 19 and Course Overview
2. Understanding Transitions and useTransition
3. The New React Compiler
4. Actions in React 19
   • Form Actions and useActionState Hook
5. Optimistic Updates with useOptimistic
6. Form Status Handling with useFormStatus
7. Improved Ref Forwarding in React 19
8. The New use API
9. Support for Document Metadata
10. Summary and Next Steps

1. Introduction to React 19 and Course Overview

React 19 is at the release candidate phase, offering major new APIs and improvements. This guide covers:

• New handling paradigms for actions and mutations
• Performance enhancements via a new compiler