Closure Library vs core-js

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

Top sites by authority

Closure Library · core-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

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

United States 7,941

1,295,217

India 5,225

433,567

Brazil 3,364

406,300

United Kingdom 2,878

402,603

Germany 2,360

384,505

France 2,650

315,055

Italy 2,538

302,259

Canada 2,394

295,823

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 Closure Library sites · All core-js sites