Core Web Vitals: WordPress & Astro vs the Competition
▼ Summary
– Duda ranked first in Core Web Vitals performance with 85% of sites receiving a good score, while WordPress ranked last with 49%.
– Page weight does not always predict Core Web Vitals performance; Shopify had high page weight (3.77 MB) but ranked third in CWV due to efficient handling of complexity.
– Shopify’s strong CWV scores stem from stable rendering, layout stability, quick interactivity, and aggressive CDN optimization, despite low Lighthouse audit scores.
– Platforms with lighter page weights, like Astro (1.65 MB), generally performed well, but low page weight does not guarantee good CWV if rendering is inefficient.
– The key takeaway is that managing web page complexity is more important than minimizing page weight for achieving strong real-world Core Web Vitals performance.
The latest Core Web Vitals Technology Report from HTTP Archive delivers an unexpected finding: page weight and Lighthouse audit scores do not always align with real-world Core Web Vitals performance. The report ranks seven content management platforms, revealing nuanced insights that challenge conventional wisdom about website optimization.
Core Web Vitals (CWV) are Google’s metrics measuring how quickly a page loads, how stable it remains during rendering, and how responsive users perceive it to be. While CWV is a minor ranking factor, strong scores directly benefit site owners through faster user experiences, higher conversion rates, and improved ad performance. Poor scores create friction that drives abandonment and hurts conversions.
The assumption that page weight drives CWV scores holds in many cases, but the data shows a more complex relationship. HTTP Archive’s median page weight dataset, combined with real-world field data from the Chrome UX Report (CrUX) and lab-based testing, reveals that lighter pages often correlate with better CWV, but exceptions prove the rule.
Duda leads the rankings with approximately 85% of sites earning a good CWV score and a median page weight of just 1.78 MB. Wix follows at roughly 80% good scores with a heavier 2.55 MB median. Shopify claims third place with 79% good scores, despite having the heaviest median page weight at 3.77 MB and the lowest Lighthouse audit scores. This anomaly is striking because e-commerce sites typically suffer from third-party scripts, tracking, and complex features.
The data reveals that Lighthouse lab scores and real-world CrUX measurements reward different things. Lighthouse penalizes JavaScript payloads, unused code, render-blocking resources, and image inefficiencies. CrUX captures actual user experience, including caching, CDN effects, repeat visits, and real device conditions. Shopify succeeds in the real world because its architecture maintains stable rendering, avoids layout shifts, delivers interactivity quickly, and aggressively optimizes resource delivery through its CDN and hosting environment.
Astro ranks fourth with 67% good scores and the lightest median page weight at 1.65 MB. However, Astro’s strong performance may partly reflect the simpler sites typically built with it, such as blogs that lack complex functionality. The out-of-the-box advantage could fade as complexity increases.
Drupal sits fifth with 64% good scores and a 2.28 MB median page weight, showing stable performance from January through April 2026 but no upward improvement. Joomla ranks sixth at 58% good scores, despite a relatively light 2.53 MB median page weight. Its low Lighthouse scores suggest execution issues like render-blocking resources, inefficient JavaScript, and poor template quality are dragging down real-world performance.
WordPress finishes last with only 49% of sites achieving good CWV scores. It ranks second-to-last in Lighthouse audits and page weight, with a median of 2.63 MB. The gap between WordPress and top performers like Duda (1.87 MB) and Astro (1.65 MB) is significant enough to place them in different performance tiers.
The central insight is clear: lighter pages generally help, but they do not guarantee strong CWV performance. Shopify’s example proves that a platform can carry heavy payloads and still deliver excellent real-world results if its architecture efficiently manages complexity. The real competitive advantage belongs to platforms that handle complex features without sacrificing user experience.
Core Web Vitals break down into three specific failure points. Largest Contentful Paint (LCP) suffers when oversized images, delayed main image discovery, or render-blocking CSS and JavaScript force browsers to compete for resources. Interaction to Next Paint (INP) degrades when third-party scripts, tracking, hydration overhead, or excessive JavaScript blocks the main thread. Cumulative Layout Shift (CLS) occurs when images lack dimensions, late-loading ads, or dynamic content pushes elements around during user interaction.
Shopify naturally includes many elements that damage LCP, INP, and CLS, yet it still outperforms lighter platforms. The takeaway for SEOs and site owners is that real-world CWV success depends less on minimizing page weight and more on how effectively a platform manages the technical failure points that degrade user experience.
(Source: Search Engine Journal)
