How do I manage global state in a React app?

Managing global state in a React app depends on the complexity of your application, the size of the team, and your specific needs around state sharing and updates. **React Context API** is a built-in feature that lets you share state across your component tree without passing props down manually at every level. It’s great for simple to moderately complex apps where you need to share things like user authentication status, theme settings, or language preferences. The Context API is lightweight, requires no additional libraries, and integrates seamlessly with React hooks like `useContext` and `useReducer`. However, for very large or frequently updated state, it can lead to performance issues because any change in context causes all consuming components to re-render. **Redux** is a more robust and feature-rich state management library, often used in larger or more complex applications. It centralizes your entire app state in a single store, enforces predictable state updates via pure reducer functions, and supports powerful developer tools like time-travel debugging and middleware for side effects. Redux has a steeper learning curve and requires more boilerplate code, but libraries like Redux Toolkit have simplified setup and usage significantly. If your app involves complex state logic, asynchronous data fetching, or you want a clear separation of concerns, Redux is often a solid choice. There are also other alternatives worth considering: - **Recoil**: Provides a more fine-grained, atom-based state management solution designed to work seamlessly with React’s concurrent features. - **Zustand**: A minimal and flexible state management library with a straightforward API and no boilerplate. - **MobX**: Uses observable state and reactions, offering a more reactive programming style. **In summary:** - Use **Context API** for simple global state that doesn’t update too frequently or deeply affect performance. - Use **Redux** (especially with Redux Toolkit) for complex state management, large apps, or if you want powerful dev tools and middleware support. - Evaluate newer libraries like **Recoil** or **Zustand** if you want simpler or more modern alternatives. Choosing the right approach depends on your app’s scale, performance needs, and developer preferences. For many apps, starting with Context API is sufficient, and you can migrate to Redux or another library later if needs grow.