The useDebugValue hook displays custom labels for hooks in React DevTools. Here's how to use it effectively.
Basic Usage
Loading code block...
With Custom Hooks
Loading code block...
Deferred Formatting
Loading code block...
Multiple Debug Values
Loading code block...
Authentication Hook
Loading code block...
Form State Hook
Loading code block...
Timer Hook
Loading code block...
WebSocket Hook
Loading code block...
Media Query Hook
Loading code block...
Composed Hooks
Loading code block...
Conditional Debug Value
Loading code block...
Complex State Debugging
Loading code block...
Best Practices
When to Use:
✓ Custom hooks in libraries
✓ Complex hook state
✓ Debugging during development
✓ Team collaboration
Format Function:
✓ Use for expensive formatting
✓ Keep formatting simple
✓ Return readable strings
✓ Handle null/undefined
Content:
✓ Show relevant state
✓ Use concise labels
✓ Include counts/status
✓ Format dates/objects
Avoid:
✗ Using in every hook
✗ Complex computations
✗ Sensitive data
✗ Production overhead
Conclusion
useDebugValue enhances custom hooks with descriptive labels in React DevTools. Use the deferred formatting function for expensive operations to avoid performance impact. Focus on displaying the most relevant state information that helps during debugging. It's most valuable for reusable hooks in libraries or complex application hooks that benefit from clear state visibility.