Well Firefox recently integrated a full webpage translation, fully done local on your system. It works pretty well in my experience.

I don't know of any, just commenting to keep track of this post and add engagement.

I heard about Argos Translate, which is used by libretranslate github link. It can be used for offline translations.

But I was unable to get it running locally on my machine to test it. As far as i know they translate by routing many different translators together, which may produce worse results (for example French -> English -> Chinese

It’s been awhile but I have liked using this since its European and has been tested with my buddy’s Argentine girlfriend about accuracy and a few of my discord buddy’s from Kuwait. https://support.deepl.com/hc/en-us/articles/4407580229522-Translate-with-the-browser-extensions