A Website Performance Checklist That Actually Works

Most performance checklists list twenty things with no sense of priority. In practice, five or six fixes usually account for the vast majority of the improvement - here's the order we actually work through.

Images first, always

In nearly every audit we run, unoptimized images are the single largest contributor to slow load times. Modern formats, responsive sizing and lazy loading below the fold typically deliver the biggest single improvement.

• Convert to WebP or AVIF with fallbacks
• Serve responsive sizes via srcset, not one large image everywhere
• Lazy-load everything below the first viewport

Then third-party scripts

Chat widgets, analytics, ad pixels and A/B testing tools frequently account for more JavaScript weight than your actual application code. Auditing and deferring non-critical scripts is the second-biggest lever.

Then fonts and critical CSS

Web fonts loaded without proper fallback strategies cause layout shift and delayed text rendering. Font-display swap and preloading key fonts solves most of this.

Frequently Asked Questions