So where are you referring that google translate that Chrome can do or something else? Firefox browser has it's own simple translator but if your looking for on-the-fly like Chrome it doesn't have that only Chrome has that.

Hi Jon, you could look at the following extension. I use this a bit more often than the built-in one because it covers a lot more languages. It adds a button in the address bar and an item on the right-click context menu.

https://addons.mozilla.org/firefox/addon/traduzir-paginas-web/