What does the React Compiler do automatically that developers used to do manually?

React Compiler auto-memoizes components by analyzing render patterns, eliminating useMemo, useCallback, and React.memo across entire codebases. Traces prop dependencies at build time, skips re-renders precisely, reduces bundle 25% with zero code changes.

Example:-

Code

// Compiler auto-optimizes - no manual memo needed
function ProductGrid({ products, filter }) {
  const filtered = products.filter(p => p.name.includes(filter));
  return filtered.map(p => <Product key={p.id} {...p} />);
}