IIS vs Uvicorn
Head-to-head usage across the sites we track.
Top sites by authority
IIS · Uvicorn · how many of each technology's sites sit in the web's highest authority tiers
Open Page Rank 9+
50
3
Open Page Rank 8+
1,251
32
Open Page Rank 7+
4,874
76
Open Page Rank 6+
9,276
101
Open Page Rank 5+
15,469
134
Open Page Rank scores 0 to 10 from the open web link graph; 9+ covers only a few hundred domains worldwide.
By country
IIS · Uvicorn · share of sites in each country using one or the other
United States
114,450
537
India
56,424
377
United Kingdom
41,553
255
Italy
38,779
198
Brazil
33,870
249
Canada
30,741
224
Türkiye
30,712
156
Germany
30,381
328
Audience countries from the Chrome UX Report, top markets of either technology.
Real user performance
| Metric | IIS | Uvicorn |
|---|---|---|
| LCP | 1.6 s | 1.8 s |
| INP | 75 ms | 75 ms |
| CLS | 0 | 0 |
| TTFB | 600 ms | 700 ms |
Median site's p75 values from the Chrome UX Report, Oct 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.
Uvicorn to IIS
| Domain | When |
|---|---|
| linestreetvet.com | May 2026 |
| bemidjivethospital.com | Feb 2026 |