title: Facebook API: How to get the FB login user's unique ID? ID from API doesn't match 'real' user ID in v2.0
body: <pre><code>- (void)loginViewFetchedUserInfo:(FBLoginView *)loginView user:(id&lt;FBGraphUser&gt;)user 
  {
      self.profilePictureView.profileID = user.objectID;
      self.nameLabel.text = user.name;
      NSLog(@"My ID:%@", user.objectID);
  }
  </code></pre>
  
  <p>I have tried to print the user id using the above code. And what I get is <code>3176144783XXXXX</code>.</p>
  
  <p>However, I got a different one using this online tool <a href="http://findmyfacebookid.com/" rel="noreferrer">http://findmyfacebookid.com/</a>. The result is <code>1000042591XXXXX</code>.</p>
  
  <p>Does anyone know the difference? Why do my app and 'findmyfacebookid.com' receive a different user ID for the same user?</p>
  
  <p>Note: My mobile app need to use the FB unique ID to create my own user database. So this is the reason I need a unique ID.</p>