title: Is there any standard URL for detecting presence of captive portal?
body: <p>I am writing an application wherein I would like to check if the user is connected to the Access Point, but network access is not permitted(due to presence of captive portal).</p>
  
  <p>The following URL is a test server from Microsoft, and if everything is successful then it returns HTTP 200 , with content as "Microsoft Connect Test"
  <a href="http://www.msftconnecttest.com/connecttest.txt" rel="nofollow noreferrer">http://www.msftconnecttest.com/connecttest.txt</a></p>
  
  <p>To return the status back to the user, I would like to double check with one more test server, which returns some content in the HTML response.</p>
  
  <p>There is one test server from Google as "<a href="http://connectivitycheck.gstatic.com/generate_204" rel="nofollow noreferrer">http://connectivitycheck.gstatic.com/generate_204</a>", but this gives empty HTML response.</p>
  
  <p>Couple of servers are available from Mozilla and Apple, but all returns "SUCCESS" in HTML response.</p>
  
  <p>Why I dont prefer any test server which returns merely "SUCCESS" in HTML body is because, it doesnt allow me to test the scenario of content tamper attack.</p>
  
  <p>pl reply if you know any other standard server to test captive portals...</p>
  
  <p>~Ashish</p>