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 436,711

174,846

India 243,576

77,587

Brazil 230,631

43,920

Germany 191,904

63,127

United Kingdom 161,912

65,581

France 156,599

54,266

Japan 181,403

26,796

Italy 140,074

56,155

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, 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.

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