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
36
Open Page Rank 8+
4
649
Open Page Rank 7+
17
2,698
Open Page Rank 6+
38
5,893
Open Page Rank 5+
60
12,351
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
257
215,676
India
174
110,602
Japan
106
82,773
Brazil
93
80,295
France
134
74,632
United Kingdom
199
72,179
Spain
139
67,753
Italy
125
63,679
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | Glassbox | Site Kit |
|---|---|---|
| LCP | 2 s | 2.4 s |
| INP | 100 ms | 75 ms |
| CLS | 0 | 0 |
| TTFB | 700 ms | 1300 ms |
Median site's p75 values from the Chrome UX Report, Jun 2026. Lower is better; green meets Google's "good" threshold. This describes the sites that use each technology, not the technology's own overhead.