Can I detect what webserver a website is using?

Question

Is there any program or command that I can use to detect what webserver a website is using? With webserver I mean in software i.e. IIS 6, Apache or nginx.

Answer 1

You can use Netcraft What's That Site Running for a one off query.

You can use

wget --save-headers superuser.com

Which will dump the server headers into a new file index.html which you can then view in a text editor.

Eg, for this site:

HTTP/1.1 200 OK
Cache-Control: private
Content-Type: text/html; charset=utf-8
Expires: Tue, 16 Mar 2010 22:54:59 GMT
Server: Microsoft-IIS/7.5
Date: Tue, 16 Mar 2010 22:54:58 GMT
Connection: keep-alive
Content-Length: 119466

Answer 2

For a public website, you can use Netcraft - http://netcraft.com/. It allows you to plug in a website's address, and it will analyze the headers and tell you the webserver in use.