The Hidden Costs of Slow Sites
Every 100ms of load time costs you conversions. But here's what most developers miss: the biggest performance wins often come from the least obvious places. After optimizing hundreds of Shopify stores, I've found the real treasure isn't always where you'd expect.
The Usual Suspects (That Everyone Gets Wrong)
Images: Yes, optimize them. But don't stop at compression. Use modern formats (WebP, AVIF), implement proper srcset for responsive images, and lazy load everything below the fold. The real win? Preload your LCP image.
Third-Party Scripts: That review widget, chat popup, and analytics suite? They're probably costing you 2-3 seconds. Audit ruthlessly. Defer everything non-critical. Consider server-side alternatives.
Theme Bloat: Your premium theme came with 47 features. You use 5. Every unused feature still loads JavaScript and CSS. Strip it down or consider a custom solution.
The Hidden Gold Mines
1. Predictive Prefetching
Use the Speculation Rules API to prefetch pages users are likely to visit. When they click, the page appears instantly.
2. Critical CSS Inlining
Extract and inline above-the-fold CSS. Defer the rest. This alone can improve FCP by 40%+.
3. Font Loading Strategy
Font flash (FOUT) kills perceived performance. Use font-display: swap, preload critical fonts, and consider system font stacks for body text.
4. Liquid Optimization
Nested loops, excessive forloop.index checks, and redundant object access add up. Cache repeated Liquid operations.
Measuring What Matters
Core Web Vitals matter, but don't optimize blindly. Focus on:
- LCP - Usually your hero image or main heading
- CLS - Reserve space for dynamic content
- INP - The new metric that replaced FID
Need a performance audit for your store? Get in touch.