It claims to use the goo.gl URL shortener but actually uses https://is.gd/. I don't recognize or trust that site, and I REALLY don't trust this add-on since it doesn't do what it claims to do.

Doesnt work at all

Tried clicking the "copy shortened" button and it never does anything. Uninstalled..

The copy/paste/shorten works OK (it's just clunky).

The automatic "shorten current URL" doesn't work at all.

Sad to say, but this is the best URL shortener I've found for FF Quantum.

Super