When you use the 'Quo Vadis?' add-on, you do so for a specific purpose: to see which URL redirections take place for a specific link on any given page. The 'Quo Vadis?' add-on probes the link and is informed directly by the browser about which URL redirections take place. The results are shown immediately, and only to you, in a temporary HTML element. No data is stored or tracked by this add-on about any URL.