React 19

React 19 is a major performance and ergonomics upgrade: It ships the React Compiler and simplifies data mutations with Server/Client Actions.

React 19 is a significant leap, driving performance and developer experience with two core technologies: the **React Compiler** and **Actions**. The Compiler automatically optimizes re-renders, effectively eliminating the need for manual memoization via `useMemo` and `useCallback` . This delivers a performance boost with zero code changes. **Actions** simplify data mutations, such as form submissions, by integrating with concurrent features to automatically manage pending states, errors, and optimistic updates using new hooks like `useActionState` and `useOptimistic` . Additionally, the release stabilizes **React Server Components** for faster initial page loads and introduces the `use()` hook for reading promises or context directly .

https://react.dev/blog/react-v19