React vs Underscore.j
Head-to-head usage across the sites we track.
Detections for Underscore.j end in Apr 2021. The fingerprint catalog behind our crawls no longer carries that technology as its own entry, usually because it was retired or split into more specific ones, so its figure is the last recorded and is not directly comparable with a currently tracked technology.
Top sites by authority
React · Underscore.j · how many of each technology's sites sit in the web's highest authority tiers
Open Page Rank scores 0 to 10 from the open web link graph; 9+ covers only a few hundred domains worldwide.
By country
React · Underscore.j · share of sites in each country using one or the other
United States
596,374
0
India
237,671
0
United Kingdom
191,623
0
Germany
162,924
0
Brazil
161,653
0
Canada
147,238
0
France
140,452
0
Australia
101,917
0
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | React | Underscore.j |
|---|---|---|
| LCP | 1.9 s | 1.8 s |
| INP | 75 ms | 75 ms |
| CLS | 0 | 0 |
| TTFB | 700 ms | 1200 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.