Remove WWW prefix from your website

Question

How does Stack Overflow (and other web sites) remove the \'www\' prefix when it\'s entered as part of a URL?

Is it a redirect, a rewrite or something else entirely?<

Answer 1

You can do what mod_rewrite does for Apache, with a comparable URL rewriter for IIS. A good one is IIRF. The rule is:

RewriteCond  %{HTTP_HOST}  ^www\.example\.com$     [I]
RedirectRule ^(.*)$        http://example.com/$1   [R=301]

You can also wildcard the hostname like so:

RewriteCond  %{HTTP_HOST}  ^(.+)\.example\.com$    [I]
RedirectRule ^(.*)$        http://example.com/$1   [R=301]

IIRF is free to use.