HTTP Archive Core Web Vitals Report Shows Page Weight Not Sole Predictor of CWV

The latest Core Web Vitals Technology Report from HTTP Archive ranks seven content management platforms and finds that page weight and Lighthouse scores do not always predict real‑world CWV performance. Duda tops the list with 85% of sites scoring good CWV and a median page weight of 1.78 MB, while Shopify ranks third with 79% good CWV but the highest page weight at 3.77 MB. WordPress falls to the bottom with only 49% good CWV and a median weight of 2.63 MB, illustrating that lighter platforms tend to perform better but are not guaranteed high CWV. The report also shows that Lighthouse audit scores diverge from real‑world metrics, with Shopify’s low audit scores not preventing strong CWV outcomes due to CDN and rendering optimizations.

Astro, with the lightest median weight of 1.65 MB, achieves 67% good CWV, while Drupal and Joomla sit in the middle with 64% and 58% respectively. The findings confirm that page weight is a factor but not the sole determinant of CWV, and that efficient handling of page complexity can offset heavier payloads. The study highlights the need to benchmark against industry averages and to focus on both payload size and execution efficiency. Agencies should use these insights to prioritize performance improvements that align with user experience goals.