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 136,825

8,015

India 68,343

3,169

United Kingdom 49,161

3,552

Italy 46,831

2,104

Brazil 38,951

2,611

Germany 36,200

2,719

Canada 36,284

2,500

Türkiye 36,724

1,801

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 IIS sites · All Kestrel sites