URL reduction (or short link building) is a technique used on the Internet that makes a page accessible through a very short URL.
The general principle of URL reduction is to assign a unique key of a few characters to a specific web page. A user wishing to go to this web page can then simply provide this key after the domain name of such a reduction service, which redirects it (URL redirection) to the appropriate page.
A key is generated if a service user requests it for a specific page. The methods of generating this key vary according to the implementations:
some services generated the keys sequentially from the 26 letters of the basic Latin alphabet and the 10 digits;
enfin, certains offrent la possibilité à l’utilisateur de spécifier lui-même la clé.