Performance
Lab data — simulated mobile 40
Before 54 After
Lab metrics
Metric
Before
With Turbulence
Speed Index SI
Before: 6.5 s
After: 11 s
First Contentful Paint FCP
Before: 5.6 s
After: 11 s
Largest Contentful Paint LCP
Before: 20 s
After: 18 s -9%
Cumulative Layout Shift CLS
Before: 0.146
After: 0.083 -43%
Total Blocking Time TBT
Before: 549 ms
After: 91 ms -84%
What changed (2)
- Speculation rules prefetching Browser prefetches likely navigation targets for instant loads
- Resource hints injected Browser knows what to fetch early
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.