Cart Functionality vs Fastspring
Head-to-head usage across the sites we track.
Top sites by authority
Cart Functionality · Fastspring · how many of each technology's sites sit in the web's highest authority tiers
Open Page Rank 9+
146
0
Open Page Rank 8+
2,468
2
Open Page Rank 7+
10,226
4
Open Page Rank 6+
20,356
4
Open Page Rank 5+
37,111
6
Open Page Rank scores 0 to 10 from the open web link graph; 9+ covers only a few hundred domains worldwide.
By country
Cart Functionality · Fastspring · share of sites in each country using one or the other
United States
737,680
41
United Kingdom
239,464
23
India
207,201
26
Germany
196,505
16
France
181,709
14
Canada
166,395
18
Brazil
145,168
17
Italy
138,310
12
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | Cart Functionality | Fastspring |
|---|---|---|
| LCP | 1.7 s | 1.8 s |
| INP | 75 ms | 50 ms |
| CLS | 0 | 0 |
| TTFB | 700 ms | 1000 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.