var nVer = navigator.appVersion;
var nAgt = navigator.userAgent;
var browserName  = navigator.appName;
var fullVersion  = ''+parseFloat(navigator.appVersion);
var majorVersion = parseInt(navigator.appVersion,10);
var nameOffset,verOffset,ix;

// In Opera, the true version is after "Opera" or after "Version"

if ((verOffset=nAgt.indexOf("Opera"))!=-1) {
 browserName = "Opera";
 fullVersion = nAgt.substring(verOffset+6);
 if ((verOffset=nAgt.indexOf("Version"))!=-1)
   fullVersion = nAgt.substring(verOffset+8);
}
// In MSIE, the true version is after "MSIE" in userAgent

else if ((verOffset=nAgt.indexOf("MSIE"))!=-1) {
 browserName = "Microsoft Internet Explorer";
 fullVersion = nAgt.substring(verOffset+5);
}
// In Chrome, the true version is after "Chrome"

else if ((verOffset=nAgt.indexOf("Chrome"))!=-1) {
 browserName = "Chrome";
 fullVersion = nAgt.substring(verOffset+7);
}
// In Safari, the true version is after "Safari" or after "Version"

else if ((verOffset=nAgt.indexOf("Safari"))!=-1) {
 browserName = "Safari";
 fullVersion = nAgt.substring(verOffset+7);
 if ((verOffset=nAgt.indexOf("Version"))!=-1)
   fullVersion = nAgt.substring(verOffset+8);
}
// In Firefox, the true version is after "Firefox"

else if ((verOffset=nAgt.indexOf("Firefox"))!=-1) {
 browserName = "Firefox";
 fullVersion = nAgt.substring(verOffset+8);
}
// In most other browsers, "name/version" is at the end of userAgent

else if ( (nameOffset=nAgt.lastIndexOf(' ')+1) <
          (verOffset=nAgt.lastIndexOf('/')) )
{
 browserName = nAgt.substring(nameOffset,verOffset);
 fullVersion = nAgt.substring(verOffset+1);
 if (browserName.toLowerCase()==browserName.toUpperCase()) {
  browserName = navigator.appName;
 }
}

// trim the fullVersion string at semicolon/space if present

if ((ix=fullVersion.indexOf(";"))!=-1)
   fullVersion=fullVersion.substring(0,ix);
if ((ix=fullVersion.indexOf(" "))!=-1)
   fullVersion=fullVersion.substring(0,ix);

majorVersion = parseInt(''+fullVersion,10);
if (isNaN(majorVersion)) {
 fullVersion  = ''+parseFloat(navigator.appVersion);
 majorVersion = parseInt(navigator.appVersion,10);
}

document.write(''
 +'Browser name  = '+browserName+'<br>'
 +'Full version  = '+fullVersion+'<br>'
 +'Major version = '+majorVersion+'<br>'
 +'navigator.appName = '+navigator.appName+'<br>'
 +'navigator.userAgent = '+navigator.userAgent+'<br>'
)

看这里的演示..http://jsfiddle.net/hw4jM/3/

使用这个:http://www.quirksmode.org/js/detect.html

alert(BrowserDetect.browser); // will say "Firefox"
alert(BrowserDetect.version); // will say "3" or "4"

在纯Javascript中，您可以在导航器上执行RegExp匹配。使用userAgent查找Firefox版本:

var uMatch = navigator.userAgent.match(/Firefox\/(.*)$/),
    ffVersion;
if (uMatch && uMatch.length > 1) {
    ffVersion = uMatch[1];
}

如果不是Firefox浏览器，ffVersion将未定义。

参见工作示例→

这是对Kennebec答案的改进。

mbrowser=function(){
    this.spec_string=   navigator.userAgent;
    this.name=          this.get_name();
    this.version=       this.get_version();
    };

mbrowser.prototype.get_name=function(){
    var spec_string=this.spec_string;

    var matches=spec_string.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || [];
    
    // Work with the matches.
    matches=matches[2]? [matches[1], matches[2]]: [navigator.appName, navigator.appVersion, '-?'];
        
    // Trident.
    if(/trident/i.test(matches[1])){
        var temp=/\brv[ :]+(\d+)/g.exec(spec_string) || [];
        return 'IE';
        }
    
    // Chrome.
    if(matches[1]==='Chrome'){
        var temp=spec_string.match(/\bOPR|Edge\/(\d+)/)
        if(temp!=null)   {return 'Opera';}
        }   

    if((temp=spec_string.match(/version\/(\d+)/i))!=null){
        matches.splice(1,1,temp[1]);
        }
                                                                                                                       
    var name=matches[0];

    return name;
    };


mbrowser.prototype.get_version=function(){
    var spec_string=this.spec_string;

    var matches=spec_string.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || []; 

    // Work with the matches.
    matches=matches[2]? [matches[1], matches[2]]: [navigator.appName, navigator.appVersion, '-?'];

    // Trident.
    if(/trident/i.test(matches[1])){
        var temp=/\brv[ :]+(\d+)/g.exec(spec_string) || []; 
        var version=(temp[1]||'');
        return version;
        }   

    // Chrome.
    if(matches[1]==='Chrome'){
        var temp=spec_string.match(/\bOPR|Edge\/(\d+)/)
        var version=temp[1];
        if(temp!=null)   {return version;}
        }   

    if((temp=spec_string.match(/version\/(\d+)/i))!=null){
        matches.splice(1,1,temp[1]);                                                                                   
        }

    var version=matches[1];

    return version;
    };

// m=module.
var browser=new mbrowser();
console.log(browser.name);    // Chrome
console.log(browser.version); // 109

这段代码从spec_string (navigator.userAgent)中推导出浏览器名称和编号。但是有各种各样的spec_string，它们有各自的浏览器名称和编号。我没有条件去检查，但是其中的一小部分。如果你能发布一个你知道的浏览器名称和编号的spec_string，那就太好了。然后我可以相应地更新代码。

然后，我将按照以下方式慢慢地构建spec_string项的列表。

'spec_string1'=>[name,number],
'spec_string2'=>[name,number],

以后，无论何时对代码进行更改，都可以在所有已知的spec_string转换上自动对其进行测试。

我们可以一起做这件事。

<script type="text/javascript">
var version = navigator.appVersion;
alert(version);
</script>

基于已接受的答案，这是检测“Microsoft Edge”的更新

navigator.sayswho= (function(){ var ua= navigator.userAgent; var tem; var M= ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || []; if(/trident/i.test(M[1])){ tem= /\brv[ :]+(\d+)/g.exec(ua) || []; return 'IE '+(tem[1] || ''); } if(M[1]=== 'Chrome'){ tem= ua.match(/\b(OPR|Edg)\/(\d+)/); if(tem!= null) return tem.slice(1).join(' ').replace('OPR', 'Opera'); } M= M[2]? [M[1], M[2]]: [navigator.appName, navigator.appVersion, '-?']; if((tem= ua.match(/version\/(\d+)/i))!= null) M.splice(1, 1, tem[1]); return M.join(' '); })(); console.log(navigator.sayswho);