In React 19, useLayoutEffect remains a crucial hook for handling side effects that need to run synchronously after rendering but before the browser paints the screen. Unlike useEffect, which runs asynchronously, useLayoutEffect is useful when working with DOM measurements, animations, and UI updates that must be applied immediately to prevent flickering or layout shifts.

In this guide, we’ll explore the differences between useLayoutEffect and useEffect, best practices for using it efficiently, and real-world scenarios where it shines. Whether you're optimizing animations, handling scroll positions, or working with third-party libraries, mastering useLayoutEffect in React 19 will help you build smoother and more responsive applications.