Site speed directly impacts revenue. Amazon found that every 100ms of latency cost 1% in sales. Walmart saw 2% conversion improvement per second of load time reduction.
Here’s what actually moves the needle:
1. Use a CDN
Serve assets from edge locations close to your users. Limit the number of domains to reduce SSL handshake overhead.
2. Add Resource Hints
dns-prefetch and preconnect hints let browsers resolve DNS and establish connections before they’re needed.
3. Minify Everything
HTML, CSS, JavaScript—compress and minify in your build step. Tools like esbuild handle this automatically.
4. Ship Less JavaScript
JavaScript costs you twice: download time and execution time. Question every dependency. Do you need a framework to toggle a class?
5. Lazy Load Media
Native lazy loading (loading="lazy") is now widely supported. Images below the fold shouldn’t block initial render.
6. Optimize Images
Use an image CDN like Cloudinary or imgix to serve properly sized, modern formats (WebP, AVIF) automatically.
7. Optimize Video
Compress aggressively, use adaptive bitrate streaming, and never autoplay video that isn’t visible.
8. Go Static
Static assets on a CDN will always outperform dynamic server rendering. Most marketing pages and content sites can be fully static.
Measure continuously. PageSpeed Insights and Lighthouse CI catch regressions before they hit production.