Case Study: How We Cut Page Load Time by 35% (Step-by-Step)

How I Improved Page Load Speed by 35%

Here's exactly what I did to speed up a client's website.

The Problem

• Initial load time: 4.2 seconds
• Lighthouse score: 62
• High bounce rate: 58%

The Solution

1. Image Optimization (Saved 1.2s)

• Converted to WebP format
• Implemented lazy loading
• Used next/image for automatic optimization

2. Code Splitting (Saved 0.8s)

• Dynamic imports for heavy components
• Route-based code splitting
• Removed unused dependencies

3. Font Optimization (Saved 0.3s)

• Used next/font for automatic optimization
• Subset fonts to only needed characters
• Preloaded critical fonts

4. Caching Strategy (Saved 0.2s)

• Implemented service worker
• Set proper cache headers
• Used CDN for static assets

The Results

• New load time: 2.7 seconds (35% improvement)
• Lighthouse score: 94
• Bounce rate: 32% (45% improvement)

Key Takeaways

1. Images are usually the biggest bottleneck 2. Code splitting makes a huge difference 3. Every optimization compounds 4. Measure before and after

Speed matters. A faster site means better UX, better SEO, and more conversions.