Cart Functionality vs KMK
Head-to-head usage across the sites we track.
Top sites by authority
Cart Functionality · KMK · 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
0
Open Page Rank 7+
10,226
0
Open Page Rank 6+
20,356
0
Open Page Rank 5+
37,111
0
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 · KMK · share of sites in each country using one or the other
United States
737,680
0
United Kingdom
239,464
0
India
207,201
1
Germany
196,505
2
France
181,709
0
Canada
166,395
0
Brazil
145,168
0
Italy
138,310
0
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | Cart Functionality | KMK |
|---|---|---|
| LCP | 1.7 s | 1.5 s |
| INP | 75 ms | 50 ms |
| CLS | 0 | 0 |
| TTFB | 700 ms | 300 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.