core-js vs OpenCV
Head-to-head usage across the sites we track.
Top sites by authority
core-js · OpenCV · how many of each technology's sites sit in the web's highest authority tiers
Open Page Rank 9+
242
0
Open Page Rank 8+
5,108
0
Open Page Rank 7+
26,213
0
Open Page Rank 6+
57,082
0
Open Page Rank 5+
109,074
0
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 · OpenCV · share of sites in each country using one or the other
United States
1,479,835
2
India
495,926
1
United Kingdom
457,421
2
Germany
439,161
2
Brazil
420,075
0
France
369,824
1
Canada
341,001
1
Italy
336,371
1
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | core-js | OpenCV |
|---|---|---|
| LCP | 2 s | 3.3 s |
| INP | 75 ms | 75 ms |
| CLS | 0 | 0 |
| TTFB | 800 ms | 900 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.