Does exactly what I want in a minimalistic way.

Firefox Nightly for Android で使用できませんでした

Super simple et efficace: tu sélectionnes un texte, bouton droit, menu "To DeepL" ouvre un nouvel onglet avec ce texte traduit.
Thanks to @rewkha :-)

Works really easily and nicely for me! The selected text opens up in DeepL in a new tab. Have been using this for a few years now and I don't think I have ever faced any problem with it.

Great open source addon. No permissions requiered, and a better translation than with Google Translate.

Make the work with great Deepl.com-translator easy, also for paying customers as me. Big thank you the the developer.

運作正常，如果開啟是在背景標籤就更好了

在新面面打开翻译，比复制到DEEPL翻译要节约点点时间。要是能在当前页面弹出翻译小框，不用切换就完美了

After using Google Translate for years, I am IMPRESSED! DeepL's translation appear to be more accurate than Google's. Also when 'listening' to the translations, DeepL's speech is slower so the proper pronunciation of each word can be understood. Google's speech is so fast (even at the slower level) that you cannot hear the proper pronunciation.

Great GoogleTranslate alternative.
Extension needs no permissions.
I can define translation target language in about:addons preferences.
Can be good if addon asks for setting destination language after installation or detect it automatically from browser settings. Maybe that would require more permissions though.

Better quality translation than Google's...much better. Little annoying to have to right click and then 'send' it to the translator. Should use the same trick as the others, i.e. a pop up logo after selecting text.