I use the Accept-Language per site add-on [1] for this. It allows me to map top-level domains to preferred languages. Most of the time, this has worked well for

I use the Accept-Language per site add-on [1] for this. It allows me to map top-level domains to preferred languages. Most of the time, this has worked well for me on sites which respect the header. For example, `.de` sites tend to be originally written in German, so I map the `*.de` pattern to the German language. [1]: https://addons.mozilla.org/en-US/firefox/addon/accept-language-per-site/ https://addons.mozilla.org/en-US/firefox/addon/accept-langua...