Why this matters
Largest Contentful Paint measures how quickly the largest visible element loads. Target: under 2.5 seconds. Common fixes: optimise and lazy-load images (see our WebP images tip), serve from a CDN, and use server-side caching to reduce time to first byte.
Interaction to Next Paint measures responsiveness to user interactions — clicking Add to Cart, applying a filter. Target: under 200 milliseconds. Common fixes: reduce JavaScript execution time, defer non-critical scripts, optimise WooCommerce AJAX handlers. Cumulative Layout Shift measures visual stability. Target: under 0.1. Common WooCommerce causes: product image grids resizing after loading, cookie notice banners pushing content down, and font swaps causing text to reflow.
Monitor all three in Google Search Console's Core Web Vitals report, which shows field data from actual visitors. This is more valuable than lab data from PageSpeed Insights. Fix the metric with the worst real-user data first. Improvements in Core Web Vitals often require developer involvement — treat this as an ongoing technical priority. Combining good Core Web Vitals with strong content and link building creates a compounding SEO advantage.
Expert insight — Vesa Nippala
Vesa Nippala has optimised dozens of WooCommerce stores and built the ProsperCart e-commerce platform. This advice comes from real-world experience, not theory. Learn more about Vesa →
Key takeaways
- LCP target: under 2.5 seconds
- INP target: under 200ms
- CLS target: under 0.1
- Search Console field data beats lab data