title: Chrome DevTools "disable cache": what does it actually do apart from nothing (for service worker scripts)?
body: <p>I'm trying to test the behaviour of my site on the assumption that the local disk cache is empty.  I know that there are ways of clearing the cache and doing Ctrl-F5 etc each time, but there is also a "Disable Cache" checkbox in the Network tab that seems like it <em>should</em> do what I'm after... i.e. disable the cache.</p>
  
  <p>But, when I clear the cache, enable that option, and F5-reload my site a couple of times, this is what I see:</p>
  
  <p><a href="https://i.stack.imgur.com/uHIQb.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/uHIQb.jpg" alt="enter image description here"></a></p>
  
  <p>The resource has been cached, and is being served from cache, despite "disable cache" being enabled!  So what does this option actually do?</p>
  
  <p>EDIT</p>
  
  <p>Maybe this behaviour I'm seeing relates only to caching of service worker scripts?  If you load <a href="https://cdn.rawgit.com/jakearchibald/80368b84ac1ae8e229fc90b3fe826301/raw/ad55049bee9b11d47f1f7d19a73bf3306d156f43/" rel="noreferrer">this page</a> (an example linked from <a href="https://developers.google.com/web/fundamentals/instant-and-offline/service-worker/lifecycle" rel="noreferrer">this guide</a> to service workers), at least for me the <code>sw.js</code> file is fetched from disk cache even with "disable cache" enabled.</p>