The Web Performance Checklist

Performance is not an optimization — it is a feature. Slow sites lose visitors, rankings, and revenue. Here is a checklist to audit and improve your site.

Measure First

Run Lighthouse, WebPageTest, and check Core Web Vitals in Search Console. Identify your worst metrics before making changes. Profile, do not guess.

Reduce JavaScript

Ship less JavaScript. Use static rendering where possible. Lazy-load components that are not visible on initial load. Tree-shake your imports.

Optimize Images

Use modern formats (WebP, AVIF), lazy-load below-the-fold images, and serve responsive sizes with srcset. Images are typically the largest payload on any page.

Cache and CDN

Set proper cache headers. Use a CDN for static assets. Preconnect to third-party origins. Every millisecond of network latency adds up.