I recently compared various translators including Bing, Yandex, Baidu Fanyi and who knows what else and my result was DeepL beating everyone with their neural MT (which I don't think can be done offline), followed by pretty much tie between Google Translate and Reverso (which also use neural MT, same as DeepL and also their website is also confusingly very similar to DeepL, almost like clone).
Sometimes GT is better than DeepL, sometimes Reverso, but most of the time DeepL delivers the best translation, followed by GT, which is usually followed by Reverso.
But considering 2 of these use neural MT I can't imagine how good/bad is Firefox with offline translation.
I recently compared various translators including Bing, Yandex, Baidu Fanyi and who knows what else and my result was DeepL beating everyone with their neural MT (which I don't think can be done offline), followed by pretty much tie between Google Translate and Reverso (which also use neural MT, same as DeepL and also their website is also confusingly very similar to DeepL, almost like clone).
Sometimes GT is better than DeepL, sometimes Reverso, but most of the time DeepL delivers the best translation, followed by GT, which is usually followed by Reverso.
But considering 2 of these use neural MT I can't imagine how good/bad is Firefox with offline translation.