We had a discussion about this kind of thing and associated pitfalls, a couple of weeks back: https://news.ycombinator.com/item?id=23216502 https://news.ycombi

We had a discussion about this kind of thing and associated pitfalls, a couple of weeks back: https://news.ycombinator.com/item?id=23216502 https://news.ycombinator.com/item?id=23216502 After the hassles I've had with Yandex Browser [as mentioned in the above] I'd say; don't try and detect it. Let the user select their preferred language. Or, if you really insist on trying to be clever by detecting user language --for the love of all that's holy, give the user an easy way to change it if [when!] you get it wrong! Few things more annoying that a page which loads in the 'wrong' language and then, even if you select the 'right' one, automatically reloads the wrong one again, because the developer wanted to show off some fancy "I know what you want better than you do!" scripting.