§2.1 "Can the page load fast enough?"
Technical Performance and Speed Optimization
Page speed is the first thing we measure because it affects everything downstream, and a store that takes more than 3 seconds to load loses roughly 53 percent of mobile visitors before they see a single product. We test every Core Web Vital metric: Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS). Beyond those headline numbers, we audit Time to First Byte, Total Blocking Time, and the full render waterfall to identify exactly which resources are slowing your store down.
The most common speed killers on Shopify stores are uncompressed hero images served without next-gen formats, render-blocking third-party scripts from apps that load on every page regardless of need, and redundant JavaScript from 15 or more active apps where 6 could do the same work. We also check for redirect chains, broken internal links, 404 errors, and server response patterns that add invisible delay. For stores on Shopify Plus, we look at checkout extensibility performance and custom script load times that standard-plan stores do not face.