var isOpera = !!window.opera || navigator.userAgent.indexOf('Opera') >= 0;
        // Opera 8.0+ (UA detection to detect Blink/v8-powered Opera)
        var isFirefox = typeof InstallTrigger !== 'undefined';   // Firefox 1.0+
        var isSafari = Object.prototype.toString.call(window.HTMLElement).indexOf('Constructor') > 0;
        // At least Safari 3+: "[object HTMLElementConstructor]"
        var isChrome = !!window.chrome;                          // Chrome 1+
        var isIE = /*@cc_on!@*/false; 

你可以阅读更多 如何检测Safari, Chrome, IE, Firefox和Opera浏览器?

遗憾的是，IE11的导航器中不再有MSIE。

Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; OfficeLiveConnector.1.5; OfficeLivePatch.1.3; .NET4.0C; BRI/2; BOIE9;ENUS; rv:11.0) like Gecko

至于为什么你想知道你在使用哪个浏览器，这是因为每个浏览器都有自己的一组错误，你最终实现了浏览器和版本特定的解决方案，或者告诉用户使用不同的浏览器!

//Copy and paste this into your code/text editor, and try it

//Before you use this to fix compatability bugs, it's best to try inform the browser provider that you have found a bug and there latest browser may not be up to date with the current web standards

//Since none of the browsers use the browser identification system properly you need to do something a bit like this

//Write browser identification
document.write(navigator.userAgent + "<br>")

//Detect browser and write the corresponding name
if (navigator.userAgent.search("MSIE") >= 0){
    document.write('"MS Internet Explorer ');
    var position = navigator.userAgent.search("MSIE") + 5;
    var end = navigator.userAgent.search("; Windows");
    var version = navigator.userAgent.substring(position,end);
    document.write(version + '"');
}
else if (navigator.userAgent.search("Chrome") >= 0){
document.write('"Google Chrome ');// For some reason in the browser identification Chrome contains the word "Safari" so when detecting for Safari you need to include Not Chrome
    var position = navigator.userAgent.search("Chrome") + 7;
    var end = navigator.userAgent.search(" Safari");
    var version = navigator.userAgent.substring(position,end);
    document.write(version + '"');
}
else if (navigator.userAgent.search("Firefox") >= 0){
    document.write('"Mozilla Firefox ');
    var position = navigator.userAgent.search("Firefox") + 8;
    var version = navigator.userAgent.substring(position);
    document.write(version + '"');
}
else if (navigator.userAgent.search("Safari") >= 0 && navigator.userAgent.search("Chrome") < 0){//<< Here
    document.write('"Apple Safari ');
    var position = navigator.userAgent.search("Version") + 8;
    var end = navigator.userAgent.search(" Safari");
    var version = navigator.userAgent.substring(position,end);
    document.write(version + '"');
}
else if (navigator.userAgent.search("Opera") >= 0){
    document.write('"Opera ');
    var position = navigator.userAgent.search("Version") + 8;
    var version = navigator.userAgent.substring(position);
    document.write(version + '"');
}
else{
    document.write('"Other"');
}

//Use w3schools research the `search()` method as other methods are availible

如果你想要一个返回浏览器和版本的函数，这里是对原始答案的改进:

navigator.browserInfo = 
(
    function()
    {
        var browser = '';
        var version = '';
        var idString = '';

        var ua = navigator.userAgent;
        var tem = [];
        var M = ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i);

        //IE will be identified as 'Trident' and a different version number. The name must be corrected to 'Internet Explorer' and the correct version identified.
        //ie correction
        if(/trident/i.test(M[1]))
        {
            tem = /\brv[ :]+(\d+.?\d*)/g.exec(ua) || [];
            browser = 'Internet Explorer';
            version = tem[1];
        }

        //firefox
        else if(/firefox/i.test(M[1]))
        {
            tem = /\brv[ :]+(\d+.?\d*)/g.exec(ua) || [];
            browser = 'Firefox';
            version = tem[1];
        }

        //safari
        else if(/safari/i.test(M[1]))
        {
            tem = ua.match(/\bVersion\/(\d+.?\d*\s*\w+)/);
            browser = 'Safari';
            version = tem[1];
        }

        //If 'Chrome' is found, it may be another browser. 
        else if(M[1] === 'Chrome')
        {
            //opera
            var temOpr = ua.match(/\b(OPR)\/(\d+.?\d*.?\d*.?\d*)/);
            //edge
            var temEdge = ua.match(/\b(Edge)\/(\d+.?\d*)/);
            //chrome
            var temChrome = ua.match(/\b(Chrome)\/(\d+.?\d*.?\d*.?\d*)/);

            //a genuine 'Chrome' reading will result from ONLY temChrome not being null.
            var genuineChrome = temOpr == null && temEdge == null && temChrome != null;

            if(temOpr != null)
            {
                browser = temOpr[1].replace('OPR', 'Opera');
                version = temOpr[2];
            }

            if(temEdge != null)
            {
                browser = temEdge[1];
                version = temEdge[2];
            }

            if(genuineChrome)
            {
                browser = temChrome[1];
                version = temChrome[2];
            }
        }
        //There will be some odd balls, so if you wish to support those browsers, add functionality to display those browsers as well.

        if(browser == '' || version == '')
        {
            idString = 'We couldn\'t find your browser, but you can still use the site';
        }
        else
        {
            idString = browser + ' version ' + version;
        }

        alert('Your browser is ' + idString);

        //store the type of browser locally
        if(typeof(Storage) !== "undefined")
        {
            //Store
            localStorage.setItem('browser', browser);
            localStorage.setItem('version', version);
        } 
        else
        {
            alert('local storage not available');
        }
    }
)();

这样，它还将结果存储在本地，因此不必每次都执行该检查。

有时候我们需要一个简单的方法来检查浏览器是否是IE。它可能是这样的:

 var isMSIE = (/trident/i).test(navigator.userAgent);

 if(isMSIE)
 {
  /* do something for ie */
 }
 else
 {
  /* do something else */
 }

或者简化的siva方法:

 if(!!navigator.systemLanguage)
 {
  /* do something for ie */
 }
 else
 {
  /* do something else */
 }

MSIE .11契

if( (/trident/i).test(navigator.userAgent) && (/rv:/i).test(navigator.userAgent) )
{
  /* do something for ie 11 */
}

其他IE浏览器在其userAgent属性中包含MSIE字符串，并可能被它捕获。

您可以使用jQuery库来检测浏览器版本。

例子:

jQuery.browser.version

然而，这只有在你同时使用jQuery的其他函数时才有意义。对我来说，仅仅为了检测浏览器而添加整个库似乎有点小题大做。

更多信息: http://api.jquery.com/jQuery.browser/

(你需要向下滚动一点)