React Best Practices in 2025: Patterns and Anti-Patterns

# React Best Practices in 2025: Patterns and Anti-Patterns React continues to evolve, and so do best practices. Here's my comprehensive guide to writing clean, performant React code in 2025. ## Component Design ### Favor Composition Over Inheritance React's composition model is powerful. Instead of complex inheritance hierarchies, compose smaller, focused components. ### Single Responsibility Principle Each component should do one thing well. If a component is doing too much, split it. ### Use Custom Hooks for Logic Extract reusable logic into custom hooks. This keeps components clean and makes testing easier. ## State Management ### Local State First Start with local state (useState). Only reach for global state when truly necessary. ### Server State vs Client State Use React Query or SWR for server state. They handle caching, revalidation, and loading states automatically. ### Avoid Prop Drilling For deep component trees, use Context or state management libraries instead of passing props through many levels. ## Performance Optimization ### Memoization Use useMemo and useCallback appropriately - but don't over-optimize. Profile first, optimize second. ### Code Splitting Lazy load routes and heavy components to reduce initial bundle size. ### Virtual Lists For long lists, use virtualization libraries like react-window. ## Common Anti-Patterns ### 1. Premature Optimization Don't memoize everything. React is fast by default. ### 2. Giant Components Break down large components into smaller, focused ones. ### 3. Not Using Keys Properly Always use stable, unique keys for list items. ### 4. Ignoring Accessibility Build accessible components from the start. ## Testing ### Test User Behavior Test what users see and do, not implementation details. ### Integration Over Unit Tests Integration tests catch more real bugs than unit tests. ## TypeScript Integration ### Use Strict Mode Enable strict TypeScript for maximum type safety. ### Type Props Properly Define clear interfaces for component props. ## Conclusion Following these practices will help you build maintainable, performant React applications. Remember: simplicity wins.