Simply type (or copy- paste from your browser's address bar) the URL which you'd like to make smaller into the text box on the main page. Push the "Compress Address" button, and Open URL Shortener will make the address smaller for you, and give you a new link. You can then copy this new URL wherever you'd like to use it.
There is no need to visit Open URL Shortener to use a shortened address. Simply type or paste the shortened URL into your browser's address bar and press enter, you will be automatically forwarded to the original address. If somebody has given you an Open URL Shortener URL in the form of a hyperlink, just click on the link instead.
It's very easy to find out where any Open URL Shortener shortened address will take you without having to visit it. This is useful to check that the link will redirect to a destination you trust. Simply add a hyphen (dash) to the end of the shortened URL, and instead of being redirected to the original long address automatically, you'll be taken to a preview page telling you where the link goes.
For example: You have been given the shortened link http://xvr.in/b and want to check where it goes. Copy-paste it into your browser's address bar and then add a hyphen, making the link http://xvr.in/b-. Now simply visit that address, and instead of being taken directly to the original URL, you'll be taken to a preview page on the Open URL Shortener site which will tell you the link's destination.