IIS vs Kestrel

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

Top sites by authority

IIS · Kestrel · 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

IIS · Kestrel · share of sites in each country using one or the other

United States 121,069

7,499

India 60,068

2,940

United Kingdom 43,214

3,289

Italy 39,691

1,847

Brazil 35,276

2,439

Germany 31,791

2,496

Canada 31,780

2,229

Türkiye 31,323

1,606

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 IIS sites · All Kestrel sites