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/

var ua = navigator.userAgent;

if (/Firefox\//.test(ua))
   var Firefox = /Firefox\/([0-9\.A-z]+)/.exec(ua)[1];

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→

为什么不另一个解决方案:

navigator.userAgent.includes("Firefox")? log("Mozilla") :log("Chrome")

检测浏览器及其版本

此代码片段基于MDN的文章。他们给出了可以用来检测浏览器名称的各种关键字的简短提示。

为了检测Edge和UCBrowser这样的浏览器，我做了一些改动

getBrowser = () => { const userAgent = navigator.userAgent; let browser = "unkown"; // Detect browser name browser = (/ucbrowser/i).test(userAgent) ? 'UCBrowser' : browser; browser = (/edg/i).test(userAgent) ? 'Edge' : browser; browser = (/googlebot/i).test(userAgent) ? 'GoogleBot' : browser; browser = (/chromium/i).test(userAgent) ? 'Chromium' : browser; browser = (/firefox|fxios/i).test(userAgent) && !(/seamonkey/i).test(userAgent) ? 'Firefox' : browser; browser = (/; msie|trident/i).test(userAgent) && !(/ucbrowser/i).test(userAgent) ? 'IE' : browser; browser = (/chrome|crios/i).test(userAgent) && !(/opr|opera|chromium|edg|ucbrowser|googlebot/i).test(userAgent) ? 'Chrome' : browser;; browser = (/safari/i).test(userAgent) && !(/chromium|edg|ucbrowser|chrome|crios|opr|opera|fxios|firefox/i).test(userAgent) ? 'Safari' : browser; browser = (/opr|opera/i).test(userAgent) ? 'Opera' : browser; // detect browser version switch (browser) { case 'UCBrowser': return `${browser}/${browserVersion(userAgent,/(ucbrowser)\/([\d\.]+)/i)}`; case 'Edge': return `${browser}/${browserVersion(userAgent,/(edge|edga|edgios|edg)\/([\d\.]+)/i)}`; case 'GoogleBot': return `${browser}/${browserVersion(userAgent,/(googlebot)\/([\d\.]+)/i)}`; case 'Chromium': return `${browser}/${browserVersion(userAgent,/(chromium)\/([\d\.]+)/i)}`; case 'Firefox': return `${browser}/${browserVersion(userAgent,/(firefox|fxios)\/([\d\.]+)/i)}`; case 'Chrome': return `${browser}/${browserVersion(userAgent,/(chrome|crios)\/([\d\.]+)/i)}`; case 'Safari': return `${browser}/${browserVersion(userAgent,/(safari)\/([\d\.]+)/i)}`; case 'Opera': return `${browser}/${browserVersion(userAgent,/(opera|opr)\/([\d\.]+)/i)}`; case 'IE': const version = browserVersion(userAgent,/(trident)\/([\d\.]+)/i); // IE version is mapped using trident version // IE/8.0 = Trident/4.0, IE/9.0 = Trident/5.0 return version ? `${browser}/${parseFloat(version) + 4.0}` : `${browser}/7.0`; default: return `unknown/0.0.0.0`; } } browserVersion = (userAgent,regex) => { return userAgent.match(regex) ? userAgent.match(regex)[2] : null; } console.log(getBrowser());

navigator.sayswho= (function(){ var ua= navigator.userAgent, tem, 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|Edge)\/(\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); // outputs: `Chrome 62`