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 8,763

1,479,835

India 6,090

495,926

United Kingdom 3,315

457,421

Germany 2,722

439,161

Brazil 3,852

420,075

France 3,031

369,824

Canada 2,699

341,001

Italy 2,746

336,371

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 Closure Library sites · All core-js sites