Based on this extremely helpful post, a slight extension to make it easier to use wrk with a HTTP proxy. url = '' host = '' init = function(args) url = args[1] -- proxy needs absolute URL -- Capture the hostname from the target URL. _, _, host = string.find(url, 'http://([^/]+)/') end request = function() return wrk.format("GET", url, { Host = host }) end Usage is like this: $ wrk -s proxy.