Headline: React Compiler â formerly React Forget â shipped stable with React 19 and automatically memoizes components, hooks, and callbacks by analyzing data flow at build time. No dependency arrays to write; the compiler infers them. Here is what it handles, when it opts out, and whether you should delete your useMemo calls.
Key takeaways
React Compiler inserts useMemo, useCallback, and React.memo automatically at build time â no dependency arrays to maintain.
Enable it in Next.js 15/16 with experimental.reactCompiler: true in next.config.ts.
The compiler is conservative: if it cannot prove memoization is safe, it emits the component unchanged.
