midReact Hooks
What is useLayoutEffect?
Updated May 6, 2026
Short answer
useLayoutEffect runs synchronously after DOM mutations.
Deep explanation
It blocks painting until effect execution completes, useful for measuring layout.
Real-world example
Measuring element size before rendering UI adjustments.
Common mistakes
- Using it for async API calls.
Follow-up questions
- Difference between useEffect and useLayoutEffect?
- Can it affect performance?