core-js vs Zepto

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

Top sites by authority

core-js · Zepto · 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

core-js · Zepto · share of sites in each country using one or the other

United States 1,295,217

10,149

India 433,567

4,916

Brazil 406,300

2,650

United Kingdom 402,603

3,891

Germany 384,505

3,067

France 315,055

2,827

Italy 302,259

2,462

Canada 295,823

3,310

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, 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.

Sites that switched

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

All core-js sites · All Zepto sites