Smooth Async Transitions in React 19

React 19's async transitions using the useTransition hook enable non-blocking form experiences by marking state updates as low priority. This keeps the UI responsive during API calls and async operations. The feature supports optimistic updates for instant feedback, integrates with Server Actions for simplified server communication, and provides granular control over urgent vs non-urgent updates. Key benefits include maintaining form interactivity during submissions, graceful error handling, and improved perceived performance on slow networks or devices.