Performance
Lab data — simulated mobile 38
Before 48 After
Lab metrics
Metric
Before
With Turbulence
Speed Index SI
Before: 7.7 s
After: 14 s
First Contentful Paint FCP
Before: 5.0 s
After: 4.2 s -16%
Largest Contentful Paint LCP
Before: 7.1 s
After: 12 s
Cumulative Layout Shift CLS
Before: 0.008
After: 0.074
Total Blocking Time TBT
Before: 1.0 s
After: 350 ms -66%
What changed (4)
- Speculation rules prefetching Browser prefetches likely navigation targets for instant loads
- Resource hints injected Browser knows what to fetch early
- Off-screen images lazy-loaded Images load as they scroll into view
- Font display swap + DNS preconnect Text shows up while fonts load
How we measured this
- 1. We fetched your page and scored it with PageSpeed Insights (mobile, lab data).
- 2. We re-fetched it through a Turbulence preview environment that applies our transformation pipeline.
- 3. We scored the result with PageSpeed Insights again.
- 4. The deltas above are the difference — a directional estimate, not a forecast. First visits, geographic location, network conditions, and JS-rendered content all affect real-world results.