title: HTTP request cost vs. page size cost?
body: <p>I know it's a good practice to minimize the number of requests each page needs.  For example, combining javascript files and using css sprites will greatly reduce the number of requests needed to render your page.</p>
  
  <p>Another approach I've seen is to keep javascript embedded in the page itself, especially for javascript specific to that page and not really shared across other pages.</p>
  
  <p>But my question is this:</p>
  
  <p>At what point does my javascript grow too large that it becomes more efficient to pull the script into a separate file and allow the additional request for the separate js file?</p>
  
  <p>In other words, how do I measure how much bytes equates to the cost of one request?</p>
  
  <p>Since successive requests are cached, the only cost of calling that same js file is the cost of the request.  Whereas keeping the js in the page will always incur the cost of additional page size, but will not incur the cost of an additional request.</p>
  
  <p>Of course, I know several factors go into this: speed of the client, bandwidth speed, latency.  But there has to be a turning point to where it makes more sense to do one over the other.  </p>
  
  <p>Or, is bandwidth so cheap (speed, not money) these days that it requires many more bytes than it used to in order to exceed the cost of a request?  It seems to be the trend that page size is become less of a factor, while the cost of a request has plateaued.</p>
  
  <p>Thoughts?</p>