Academy / Advanced Level: HTML and CSS

Web Performance Optimization

Optimizing JavaScript for Performance

JavaScript can significantly impact page performance if it’s not optimized. Poorly written or bloated JavaScript can lead to slow rendering and poor user experiences, especially on mobile devices.

Techniques to Optimize JavaScript:

• Minify and compress JavaScript: Use tools like UglifyJS or Terser to reduce file sizes.
• Defer non-critical scripts: Use the defer attribute to load non-critical JavaScript after the page has finished parsing.

<script src="script.js" defer></script>

• Reduce DOM manipulation: Excessive DOM manipulation can slow down performance. Optimize DOM access and updates by batching changes.
• Use Web Workers: If you have heavy computations, move them to Web Workers to prevent blocking the main thread and ensure the UI remains responsive.