title: Swapping an image during web development
body: <p>I'm trying to see what a certain webpage would look like if I replaced a certain image with another. Rather than upload the image, edit the site, etc, each time I tweak it, I'd like to know if there's a way to change the image in the page to my local version while viewing the remote page.</p>
  
  <p>I use Firebug for debugging web development usually, but I'm open to any other tool that might do this.</p>
  
  <p>(It is absolutely impossible to search for this and find anything but questions about dynamic image swapping on a deployed website, so sorry if this is a duplicate.)</p>
  
  <p><strong>Added:</strong> I just tried substituting a <code>file:///</code> URI pointing to the image (copied and pasted from the address bar after manually opening the image), and alas, it did not work — the image fails to change.</p>