As of October 8, 2026, IIS is used by 743,031 websites in the TechLeads index: 3.7% of all Web servers detections, the 6th most-used of 81 Web servers technologies.
743,031
websites using IIS
3.7%
share of Web servers
#6
of 81 in Web servers
Cite this data
Quoting these numbers? Credit TechLeads with a link to this page.
Citation
TechLeads. "IIS Customers and Market Share." Data as of October 8, 2026. https://techleads.fyi/technology/iis/market-share
In HTTP Archive's monthly crawl of public websites, IIS was detected on 1,189,059 pages in September 2026, down 20.1% from a year earlier (peak: 2,211,657). Among the 1,000 most-visited sites, it appeared on 20. HTTP Archive is a separate dataset from the TechLeads index, so its numbers are not added to ours.
Same month, other Web Servers technologies in HTTP Archive: Apache HTTP Server 8,652,140, LiteSpeed 3,072,599, OpenResty 739,473, OpenGSE 396,103, Phusion Passenger 68,394.
IIS customers by country
Based on country-code domains (such as .de or .co.uk); websites on .com and other generic domains are not assigned a country.
TechLeads scans public websites and detects IIS from signals in the page HTML, scripts, cookies, HTTP headers and DNS records. Market share is IIS's website count divided by the website counts of all Web servers technologies we track; a site using two Web servers tools counts for both. Counts were last refreshed on October 8, 2026 and update daily.
FAQ
IIS accounts for 3.7% of Web servers detections in the TechLeads index (743,031 websites), which makes it the 6th most-used of 81 Web servers technologies we track.