 <p>You don't need to set the '!' at all - except you want force your sites to be crawled by search engines (see <a href="https://developers.google.com/webmasters/ajax-crawling/docs/specification?hl=de&amp;csw=1" rel="nofollow">GoogleDevelopers Spec</a>). Some people even say, these hash bangs are <a href="http://danwebb.net/2011/5/28/it-is-about-the-hashbangs" rel="nofollow">very bad UI practice</a>.</p> <p>Or is it a requirement for your application that its whole content is indexed by search engines ?</p>