title: How to make sure browsers load the most recent version of a file after updating?
body: <p>When rolling out a new website change or web application change, sometimes browsers load old javascript or image files when you navigate to the site. Oftentimes it takes a manual refresh of the page for the browser to load in the newly updated files.</p>
  
  <p>How can I make sure that after an update, users receive the most up-to-date files the first time they load the page, rather than having to manually refresh to clear out any cached files. Is there a very reliable way to do this through sending expires headers or last modified?</p>