Performance
Lab data — simulated mobile 60
Before 65 After
Lab metrics
Metric
Before
With Turbulence
Speed Index SI
Before: 5.7 s
After: 2.8 s -51%
First Contentful Paint FCP
Before: 4.6 s
After: 2.7 s -42%
Largest Contentful Paint LCP
Before: 11 s
After: 8.8 s -23%
Cumulative Layout Shift CLS
Before: 0.000
After: 0.000
Total Blocking Time TBT
Before: 137 ms
After: 270 ms
What changed (4)
- Speculation rules prefetching Browser prefetches likely navigation targets for instant loads
- Resource hints injected Browser knows what to fetch early
- Images re-encoded to AVIF/WebP Smaller image files that look the same
- Images re-encoded to AVIF/WebP Smaller image files that look the same
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.