I've tried a few translator extensions and this is my favorite. I like that it only takes one click to get the translation, and the settings, etc. are easy to navigate and visually pleasing.

Clunky and slow sometimes, but powerful

Slow: As someone coming from the instant translation world of rikaichamp etc. the half second wait time for the translation feels pretty bad. I understand that translating any language requires online connection though, so this is pretty unavoidable. Edit: There's offline caching in the iOS version

Clunky: Many powerful options, but many of the ones actually useful for me are clunky. E.g.
- Disabling the popups takes 4 clicks, a new tab, and at least 15 seconds. For an addon that changes the appearance of the page whenever one selects any(!) text, this should be a huge and obvious switch right in the toolbar options.
- When a word is selected, the "translate page" right click entry should disappear, so I don't have to navigate my mouse through the tiny 25px "2 options here >" line
- The phonetic transcription, and voice pronunciation, is for the translation target? I know how to pronounce English
- Options in the on-page popup open the settings page for some reason, instead of e.g. changing the target language
- Missing the click on the small popup icon unselects the selected text and leads to frustration. It should be possible to increase the clickable area (with visual feedback when mouse hover) without increasing the icon size

As someone who puts privacy above all else, I can definitely recommend this. Their privacy policy is AMAZING and written in a very simple and understandable way. Also, it's a truly fun read.
Regarding functionality and translations, it does a hell of a good job. Better than Google Translate, I would say. And not only does it translate, but it also gives you the word in IPA and turns non-latin alphabets into the latin correspondent!
I am astounded. I can only thank the developers for making a tool that is what I never knew I needed, but now don't want to live without.

Miglior estensione per tradurre le pagine...Le altre aprono aprono una nuova pagina,Mate traduce direttamente sul sito

I love it

Proprio come se fosse un amico vero che viene in tuo aiuto, l'estensione per Firefox di Mate Translate lo trovata eccezzionale basta il clic per tradurre una pagina intera, consigliato.!