React Hooks Performance: How to Avoid Unnecessary Re-renders

Performance is the concern that separates production-quality React code from tutorial-grade code. Most React applications do not have a rendering problem — but the ones that do can feel sluggish and frustrating. The key is knowing when optimization matters and what tools actually help. When Does React Re-render? A component re-renders when: Its state changes — calling setState re-renders the component and all children. Its parent re-renders — even if props haven't changed, children re-render by default. A consumed context changes — any useContext consumer re-renders when the context value updates. Every optimization technique targets one or more of these triggers. Rule 1: Don't Optimize Prematurely Wrapping every value in useMemo and every function in useCallback is not optimization — it is overhead. Memoization has a cost: storing previous values, comparing dependencies, managing cached references. If the computation is trivial, memoization costs more than recomputing. // Don't do thi