React 19: New Hooks and Concurrent Features Explained

React 19 ships with features that address the most common pain points developers face. From simplified data fetching to built-in optimistic UI patterns, this release is a major leap forward.

The use() Hook

The new use() hook reads the value of a Promise or Context during render. Unlike useEffect, use() can be called conditionally and integrates with Suspense automatically.

React Actions

Actions replace manual loading and error state management when submitting forms. React automatically handles the pending state for async form actions.

useOptimistic

Show a different state while an async action is in progress. When the action completes, React reverts to the actual state — making snappy UIs trivially simple.