optimizing-with-react-compiler

React Compiler auto-memoizes components, expensive calculations, function references, and object/array creation without manual intervention. It analyzes your code to determine what needs memoization, reducing unnecessary re-renders and improving performance in React 19 projects automatically.

Remove useMemo and useCallback when React Compiler handles the optimization automatically. However, retain manual memoization in edge cases based on profiler feedback, library requirements, or when calculations remain genuinely expensive despite compiler optimization.

Yes, React Compiler applies to component libraries and React 19 projects. It optimizes rendering performance and helps guide refactoring of components, calculations, and stable references across library code.

React Compiler automatically memoizes without code changes, while manual memoization requires explicit useMemo and useCallback calls. Compiler eliminates overhead for most cases; manual memoization persists only when profiler data or library constraints justify the cost.

Use profiler feedback to identify components with remaining performance issues. Retain manual memoization when calculations are expensive, libraries require it, or profiler data shows the optimization didn't sufficiently improve rendering.