So if im not mistaken, the top "translation" extension is literally a simple link\context menu integration to send you to the google translate website. I know this because about a year ago, i tried that one first.....

And then we have:
"Translate Web Pages by Filipe Ps"

This extension will translate the entire page basically in real time right before your eyes.... It simply uses google, yandex, or whatever Machine Translation provider you would like and translates your pages to the best of its ability into whatever language you choose. If you go into the settings of the extension, you can choose your preferred language, and your top 2 or 3 most likely target languages, and set the extension up to translate them "On SIGHT" with basically NO INPUT on your end!! The options i speak of are VERY fleshed out compared to EVERY other extension ive seen. I mean it has its own little user interface where as other extensions use a few simple toggle switches to get the job done.

Anyways, my point is, this is the most well put together extension ive seen. and im currently running no less than 9 extensions. Each one is something im impressed with but even though some of the others are more useful to me, this one just seems SO MUCH HARDER to make... but im not an expert.

ANYWAYS....

TL;DR THIS IS THE ONLY TRANSLATION EXTENSION YOU SHOULD CONSIDER!!!

parfait, c'est comme dans edge et chrome, clik droit traduire !

Перевод Богу перевода!!!!

Отличное расширение! Попробовал несколько, работа этого расширения понравилась больше всех.

Wonderful product, works fast and well, fixes the only thing that made Firefox difficult to use.

finally a translator that doen't translate in a separate tab

excelente

¡Justo lo que buscaba, simple automático, al estilo de facebook!

Хорошо работает. Мне понравилось