Bootstrap vs UIKit

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

Top sites by authority

Bootstrap · UIKit · 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

Bootstrap · UIKit · share of sites in each country using one or the other

United States 783,149

35,073

India 375,468

10,571

Germany 285,193

16,988

United Kingdom 258,945

8,666

Brazil 247,896

8,749

France 233,698

8,281

Italy 215,264

10,036

Spain 174,758

7,642

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 Bootstrap sites · All UIKit sites