Swiper vs Underscore.js

Head-to-head usage across the sites we track.

Top sites by authority

Swiper · Underscore.js · 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

Swiper · Underscore.js · share of sites in each country using one or the other

United States 491,705

196,685

India 274,591

88,983

Germany 213,155

71,501

Brazil 234,477

48,901

United Kingdom 182,905

74,584

France 185,131

65,402

Japan 207,032

31,250

Italy 160,103

65,347

Audience countries from the Chrome UX Report, top markets of either technology.

Real user performance

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.

Sites that switched

Domains that dropped one technology and adopted the other within about a year, data nobody else gives away free.

All Swiper sites · All Underscore.js sites