Web performance directly impacts user experience, conversion rates, and search rankings. A one-second delay in page load time can reduce conversions by seven percent. Here is how to make your site fast and keep it that way.
Core Web Vitals
Google’s Core Web Vitals — Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS) — provide measurable benchmarks for user experience. Target LCP under 2.5 seconds, INP under 200 milliseconds, and CLS under 0.1.
Image Optimization
Images remain the largest contributor to page weight. Use modern formats like WebP and AVIF with appropriate fallbacks. Implement responsive images with srcset to serve appropriately sized images for each device. Lazy-load images below the fold using the native loading="lazy" attribute.
Caching Strategies
Implement a layered caching approach: browser cache for static assets with long max-age headers, CDN cache at the edge for geographically distributed content, and application cache for computed or database-driven data. Use cache-busting with content hashes for immutable assets.
Code Splitting
Only ship the JavaScript a page actually needs. Frameworks like Astro handle this automatically through island architecture, but for client-heavy applications, dynamic imports and route-based splitting reduce initial bundle sizes significantly.
Monitoring
Performance optimization is not a one-time task. Set up real user monitoring (RUM) to track performance metrics from actual user sessions. Tools like SpeedCurve, Calibre, or web-vitals JavaScript library provide ongoing visibility into how real users experience your site.