我也遇到了同样的问题，于是我编写了以下前端专用库，它为多种浏览器打包了代码。代码并不多，但不用在多个网站上复制和粘贴相同的代码。

Get it: acceptedlanguages.js

使用它:

<script src="acceptedlanguages.js"></script>
<script type="text/javascript">
  console.log('Accepted Languages:  ' + acceptedlanguages.accepted);
</script>

它总是返回一个数组，按用户偏好排序。在Safari和IE中，数组总是单长度的。在FF和Chrome中，它可能不止一种语言。

如果您正在开发Chrome应用程序/扩展使用Chrome。i18n API。

chrome.i18n.getAcceptLanguages(function(languages) {
  console.log(languages);
  // ["en-AU", "en", "en-US"]
});

I can't find a single reference that state that it's possible without involving the serverside.

MSDN上:

navigator.browserLanguage navigator.systemLanguage navigator.userLanguage

从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.

此外，它看起来像是browserLanguage被弃用了，因为IE8没有列出它

我有一个黑客，我认为使用很少的代码，是相当可靠的。

把网站的文件放到子目录中。SSL到您的服务器中，并创建到存储文件的子目录的符号链接，该子目录指示您的语言。

就像这样:

ln -s /var/www/yourhtml /var/www/en
ln -s /var/www/yourhtml /var/www/sp
ln -s /var/www/yourhtml /var/www/it

使用您的web服务器读取HTTP_ACCEPT_LANGUAGE并根据它提供的语言值重定向到这些“不同的子目录”。

现在您可以使用Javascript的window.location.href来获取url，并在条件中使用它来可靠地识别首选语言。

url_string = window.location.href;
if (url_string = "http://yoursite.com/it/index.html") {
    document.getElementById("page-wrapper").className = "italian";
}

如果您不想依赖外部服务器，并且您有自己的服务器，您可以使用一个简单的PHP脚本来实现与@DanSingerman answer相同的行为。

languageDetector.php:

<?php
$lang = substr($_SERVER['HTTP_ACCEPT_LANGUAGE'], 0, 2);
echo json_encode($lang);
?>

只需从jQuery脚本中更改这几行:

url: "languageDetector.php",
dataType: 'json',
success: function(language) {
    nowDoSomethingWithIt(language);
}

如果你使用的是ASP . net MVC，你想从JavaScript中获得accept - languages头，那么这里有一个不涉及任何异步请求的变通例子。

在你的.cshtml文件中，将头部安全地存储在div的data- attribute中:

<div data-languages="@Json.Encode(HttpContext.Current.Request.UserLanguages)"></div>

然后你的JavaScript代码可以访问这些信息，例如使用JQuery:

<script type="text/javascript">
$('[data-languages]').each(function () {
    var languages = $(this).data("languages");
    for (var i = 0; i < languages.length; i++) {
        var regex = /[-;]/;
        console.log(languages[i].split(regex)[0]);
    }
});
</script>

当然，您也可以像其他人提到的那样，对其他服务器技术使用类似的方法。