title: Check if HTML contains anything visible
body: <p>I want to check in c# if an html document is "visibly empty". Checking InnerHtml is not enough, because the HTML could contain an image or an empty table.</p>
  
  <p>Are there any efficent ways to check a HTML document if there is anything, that translate to something that is not a whitespace?</p>
  
  <p>The complicated way i'm thinking of is removing every html/body/p/br Tag, whitespaces and nbsp items, and checking if anything is left</p>