title: IE caching behaviour: response 304 followed by 200's on same resource?
body: <p>I'm puzzled by the fact that I'm requesting a video file from our S3 bucket that has max-age set to 1 year. I sometimes get a 304, but far more often these are followed by multiple 200 responses. I'm trying to get this right in IE11.</p>
  
  <p><a href="https://i.stack.imgur.com/OHLTl.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/OHLTl.png" alt="enter image description here"></a></p>
  
  <p>Here are the request and response of the 304:</p>
  
  <p><a href="https://i.stack.imgur.com/vyhAI.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/vyhAI.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/eYzoC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eYzoC.png" alt="enter image description here"></a></p>
  
  <p>I also took snapshots of these requests (at another moment) with Charles proxy:</p>
  
  <p><a href="https://i.stack.imgur.com/wgxbF.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/wgxbF.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/oODqZ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/oODqZ.png" alt="enter image description here"></a></p>
  
  <p>And here are the request and response of the 200:</p>
  
  <p><a href="https://i.stack.imgur.com/69Bqa.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/69Bqa.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/VTRIe.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/VTRIe.png" alt="enter image description here"></a></p>
  
  <p>And here are the request and response as seen from Charles proxy:</p>
  
  <p><a href="https://i.stack.imgur.com/kOhlC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kOhlC.png" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/o9Tzg.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/o9Tzg.png" alt="enter image description here"></a></p>
  
  <p>The requests are triggered by a  DOM element that is first being added (that seems to be the 304) and then playback is periodically started again from the beginning in Javascript (those seem to be the 200's).</p>
  
  <p>So the question is: what have I possibly missed in settings or anything that is preventing resources like this from being cached?</p>
  
  <p>Thanks.</p>
  
  <p>P.S.</p>
  
  <ol>
  <li>Just to be clear: "Always refresh from server" is OFF</li>
  <li>I also see that the 200 responses are not like Google's "200 (from cache)", since the total download volume keeps increasing with every video load.</li>
  </ol>