title: What is the absolute safest way to find out if a URL exists or not?
body: <p>I do realize that there are different wat to check the existence of a website in C# and other languages. However, I have come to understand that some of them don't work as good. For example, this code:</p>
  <pre><code>        WebClient client = new WebClient();
          try
          {
              string response = client.DownloadString(url);
              return true;  // Successful -&gt; the website does exist.
          }
          catch
          {
              return false; // Unsuccessful -&gt; the website doesn't exist.
          }
  </code></pre>
  <p>doesn't detect <a href="http://www.bb.com" rel="nofollow noreferrer">www.bb.com</a>, although this website clearly does exist. What code should I use to be absolutely on the safe side here?</p>