JavaScript Performance Tips

Writing performant JavaScript is crucial for creating smooth user experiences.

Memory Management

Avoid Memory Leaks

• Remove event listeners when no longer needed
• Clear timers and intervals
• Avoid global variables

// Good
function setupHandler() {
  const button = document.getElementById('btn')
  const handler = () => console.log('clicked')

  button.addEventListener('click', handler)

  // Cleanup function
  return () => button.removeEventListener('click', handler)
}

DOM Optimization

• Minimize DOM manipulations
• Use document fragments for multiple insertions
• Cache DOM queries

Async Operations

Use modern async patterns:

• Promises over callbacks
• Async/await for readability
• Web Workers for heavy computations

Performance optimization is an ongoing process that requires measurement and iteration.