JavaScript for detecting browser language preference

Question

I have been trying to detect the browser language preference using JavaScript.

If I set the browser language in IE in Tools>Internet Options>General>Languages, how do I read this value using JavaScript?

Same problem for Firefox. I'm not able to detect the setting for tools>options>content>languages using navigator.language.

Using navigator.userLanguage , it detects the setting done thru Start>ControlPanel>RegionalandLanguageOptions>Regional Options tab.

I have tested with navigator.browserLanguage and navigator.systemLanguage but neither returns the value for the first setting(Tools>InternetOptions>General>Languages)

I found a link which discusses this in detail, but the question remains unanswered :(

Answer 1

navigator.userLanguage for IE

window.navigator.language for firefox/opera/safari

Answer 2

I can´t find a single reference that state that it´s possible without involving the serverside =P

MSDN on:

• navigator.browserLanguage
• navigator.systemLanguage
• navigator.userLanguage

From browserLanguage:

In Microsoft Internet Explorer 4.0 and earlier, the browserLanguage property reflects the language of the installed browser's user interface. For example, if you install a Japanese version of Windows Internet Explorer on an English operating system, browserLanguage would be ja.

In Internet Explorer 5 and later, however, the browserLanguage property reflects the language of the operating system regardless of the installed language version of Internet Explorer. However, if Microsoft Windows 2000 MultiLanguage version is installed, the browserLanguage property indicates the language set in the operating system's current menus and dialogs, as found in the Regional Options of the Control Panel. For example, if you install a Japanese version of Internet Explorer 5 on an English (United Kingdom) operating system, browserLanguage would be en-gb. If you install Windows 2000 MultiLanguage version and set the language of the menus and dialogs to French, browserLanguage would be fr, even though you have a Japanese version of Internet Explorer.

Note This property does not indicate the language or languages set by the user in Language Preferences, located in the Internet Options dialog box.

Furthermore it looks like browserLanguage is deprecated cause my IE8 don´t list it =P

Answer 3

There is no decent way to get that setting, at least not something browser independent.

But the server has that info, because it is part of the HTTP request header (the Accept-Language field, see http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.4)

So the only reliable way is to get an answer back from the server. You will need something that runs on the server (like .asp, .jsp, .php, CGI) and that "thing" can return that info. Good examples here: http://www.developershome.com/wap/detection/detection.asp?page=readHeader

Answer 4

I think the main problem here is that the browser settings don't actually affect the navigator.language property that is obtained via javascript.

What they do affect is the HTTP 'Accept-Language' header, but it appears this value is not available through javascript at all. (Probably why @anddoutoi states he can't find a reference for it that doesn't involve server side.)

I have coded a workaround: I've knocked up a google app engine script at http://ajaxhttpheaders.appspot.com that will return you the HTTP request headers via JSONP.

I intend to leave it there in perpetuity so feel free to use it in your code.

Here's some example code (in jQuery) for how you might use it

var language;
$.ajax({ 
    url: "http://ajaxhttpheaders.appspot.com", 
    dataType: 'jsonp', 
    success: function(headers) {
        language = headers['Accept-Language'];
    }
});

Hope someone finds this useful.