My code doesn't work with second level tld's like domain.co.uk The strainge thing is, that it works in php with preg_match() ^^ Here is my conf: # add www. if ($host ~ ^(?!www)) { rewrite ^/(.*)$ http://www.$host/$1 permanent; } # remove subdomain if ($host ~ "^www\.(.*)\.(.*\.([a-z]{2,4}|[a-z]{2}\.[a-z]{2}))") { set $host_without_sub $2; rewrite ^/(.*)$ http://www.$host_without_sub/$1 permanent; }