Nebula Components vs PageSpeed Insights
Google’s lab-based tool that scores page load performance using Core Web Vitals.
PageSpeed Insights (PSI) measures one dimension of a landing page: performance. It returns Core Web Vitals scores (LCP, INP, CLS) and lab diagnostics. It is the right tool for the question "is my page fast?"
What PageSpeed Insights does well
- +Free, fast, lab-based Core Web Vitals measurement
- +Clear pass/fail thresholds for LCP, INP, and CLS
- +Actionable performance diagnostics (image sizes, render-blocking resources)
- +The de facto standard for the speed component
Where it stops
- −It measures speed only. A fast page can still convert at zero - speed is one component, not conversion readiness.
- −It does not look at copy, message match, CTA clarity, proof placement, or trust signals.
- −It cannot answer "why is nobody buying" - only "is the page slow".
Where Nebula fits
- →Speed is one of the audited components in Nebula, measured against the same pass standard - but it sits alongside headline, CTA, proof, above-fold, mobile, and measurement.
- →The audit answers the question PSI cannot: given that the page is fast (or slow), which conversion component is the leak?
- →Published benchmarks show which components fail most often in the real dataset, so the diagnosis is comparative, not just absolute.
Side by side
| Dimension | PageSpeed Insights | Nebula Components |
|---|---|---|
| Job | Measure load performance (Core Web Vitals) | Measure conversion readiness across components |
| Components | LCP, INP, CLS | Message match, headline, CTA, proof, above-fold, mobile, speed, measurement |
| Output | Performance score + diagnostics | Composite score, component scores, ranked fix queue |
| Pass standard | Published (Google thresholds) | Published per component on /benchmarks |
| Dataset | Single-page lab runs | Cross-page benchmarks from completed audits |
| Price | Free | Free audit; $97 One-Leak Repair Sprint |
The honest take: use both
Use PSI for the speed dimension - it is excellent at it. Use the Nebula audit for the conversion dimensions PSI does not touch. A page that scores 95 on PSI and converts at zero has a leak PSI cannot see.
Verdict
PSI answers "is it fast?". Nebula answers "is it converting?". They measure different things; a conversion diagnosis starts where PSI ends.
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