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 7,960

1,320,418

India 5,352

439,882

Brazil 3,394

411,231

United Kingdom 2,866

404,005

Germany 2,407

391,462

France 2,590

311,727

Canada 2,337

298,167

Italy 2,378

291,018

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 Closure Library sites · All core-js sites