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
595,277
0
India
243,719
0
United Kingdom
194,085
0
Brazil
164,323
0
Germany
162,915
0
Canada
148,255
0
France
143,971
0
Spain
106,955
0
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | React | Underscore.j |
|---|---|---|
| LCP | 1.9 s | 2.3 s |
| INP | 75 ms | 50 ms |
| CLS | 0 | 0 |
| TTFB | 700 ms | 1700 ms |
Median site's p75 values from the Chrome UX Report, Sep 2026. Lower is better; green meets Google's "good" threshold. This describes the sites that use each technology, not the technology's own overhead.