[raving-richard]

Google is^H^Hwas* really bloody annoying when it comes to this. English (en-us and en) is the only language in my accept header. When I lived in Geneva though, Google always used to serve me pages in German (presumably Swiss-German). Gee, that's logical. (Geneva is a mainly French speaking city, though over 40% of the population is non-Swiss.)

Where I live now is another French speaking area. I just checked and it seems they are no longer serving French pages to me. But they were even just one year ago. (I don't use Google by default, so I don't know when they changed.)

Admittedly, that was an issue with geo-detecting rather than the website having bad language detection.

* They seemed to have stopped.

Air France is (though they have many faults) actually alright at detecting my language. And mostly gives me English pages...

[tazjin]

My accept-language header only has en_GB and en in it. Google still randomly serves me pages in Swedish and German (which are both languages I speak, but which I both explicitly disabled in my Google account settings).

The best case of this was when they launched the preview for the new Google Maps version - there was a landing page with some information and a button in the middle. This page was served to me in three languages at the same time (the header, the button and the info text) - presumably served by different internal components that all handle languages differently.

[ronaldx]

Worse: Google went through a period of normally serving me French-language pages.

I'm not in a French-speaking country. I don't have French in my accept header. I never expressed any preference towards the French language.

But, my ISP was Orange (France Telecom) and I had a variable IP from them.

[bhrgunatha]

I always have to open google.com/ncr in a separate tab which sets a session cookie (I don't accept permanent cookies from google.) I guess they've changed their logic for some places, just not where I am :(

[mrweasel]

Google has become worse when it comes to language detection. I often get Brazilian Portuguese on Google Analytics, I'm in Denmark. I believe one of by co-worker often got Russian.

[mschuster91]

IIRC google also "detects" language based on DNS geolocation, i.e. doing a dig google.com may reveal different IP addresses in every country (depending on the language).

There are some IP addresses which, when viewed "raw" like http://aaa.bbb.ccc.ddd/ will return a localized Google.