They are identical in their effect[1]. At one point they were almost identical in their implementation. Looking around at the (much larger) current React source

They are identical in their effect[1]. At one point they were almost identical in their implementation. Looking around at the (much larger) current React source seems to indicate that this is still the case. [1] https://react.dev/reference/react/useMemo#memoizing-a-function https://react.dev/reference/react/useMemo#memoizing-a-functi...