core-js vs Karma
Head-to-head usage across the sites we track.
Top sites by authority
core-js · Karma · how many of each technology's sites sit in the web's highest authority tiers
Open Page Rank 9+
243
1
Open Page Rank 8+
5,081
1
Open Page Rank 7+
26,045
1
Open Page Rank 6+
56,582
1
Open Page Rank 5+
107,942
3
Open Page Rank scores 0 to 10 from the open web link graph; 9+ covers only a few hundred domains worldwide.
By country
core-js · Karma · share of sites in each country using one or the other
United States
1,320,418
26
India
439,882
24
Brazil
411,231
21
United Kingdom
404,005
25
Germany
391,462
24
France
311,727
23
Canada
298,167
26
Italy
291,018
21
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | core-js | Karma |
|---|---|---|
| LCP | 2 s | 1.4 s |
| INP | 75 ms | 125 ms |
| CLS | 0 | 0 |
| TTFB | 800 ms | 600 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.