Fathom vs Site Kit

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

Top sites by authority

Fathom · Site Kit · 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

Fathom · Site Kit · share of sites in each country using one or the other

United States 5,128

191,744

India 1,781

94,995

Japan 615

73,790

Brazil 948

71,181

United Kingdom 3,204

64,452

France 1,325

63,629

Spain 1,088

63,132

Italy 1,062

58,351

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 Fathom sites · All Site Kit sites