Glassbox vs Site Kit
Head-to-head usage across the sites we track.
Top sites by authority
Glassbox · Site Kit · how many of each technology's sites sit in the web's highest authority tiers
Open Page Rank 9+
1
39
Open Page Rank 8+
4
636
Open Page Rank 7+
17
2,691
Open Page Rank 6+
38
5,912
Open Page Rank 5+
60
12,410
Open Page Rank scores 0 to 10 from the open web link graph; 9+ covers only a few hundred domains worldwide.
By country
Glassbox · Site Kit · share of sites in each country using one or the other
United States
241
194,442
India
153
96,669
Japan
94
73,684
Brazil
80
73,670
United Kingdom
174
63,934
France
118
62,421
Spain
127
58,678
Italy
113
55,218
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | Glassbox | Site Kit |
|---|---|---|
| LCP | 1.9 s | 2.4 s |
| INP | 125 ms | 75 ms |
| CLS | 0 | 0 |
| TTFB | 700 ms | 1300 ms |
Median site's p75 values from the Chrome UX Report, Aug 2026. Lower is better; green meets Google's "good" threshold. This describes the sites that use each technology, not the technology's own overhead.