The Problem

A mid-size fashion e-commerce brand came to us with a familiar problem: their site looked great but performed terribly. Average load time on mobile was 6.2 seconds. Their bounce rate was 58%. Conversions had plateaued despite a healthy ad spend.

The brief was simple: make it fast without touching the design.

The Audit

We started with a full performance audit across 40 pages. The findings:

• Hero images: Served as 3.4MB PNGs, uncompressed, no lazy loading

• Fonts: 6 custom font weights loaded on every page, blocking render

• Third-party scripts: 14 scripts, including 3 abandoned A/B testing tools

• JavaScript bundle: 890KB uncompressed, no code splitting

Total initial page weight: 4.1MB.

What We Fixed

Images first. Converted all product images to WebP, reduced hero images to 1400px max width, added srcset, enabled lazy loading. Image weight dropped from 3.4MB to 380KB.

Fonts second. Reduced to 3 font weights, preloaded the primary weight, switched to font-display: swap. Load time saved: ~800ms.

Scripts third. Removed 3 dead scripts, deferred 6 non-critical scripts. Main thread blocking time dropped by 1.2 seconds.

JavaScript last. Route-based code splitting. Initial bundle dropped from 890KB to 210KB.

The Results

• Load time: 6.2s → 2.4s (61% improvement)

• LCP: 5.8s → 1.9s (passing Core Web Vitals)

• Bounce rate: 58% → 41%

• Conversion rate: +23%

The design was untouched. The only thing that changed was how fast it loaded.