Browser Name

JavaScript FAQ | Client & Browser Configuration FAQ  

Question: How do I detect the browser name (vendor)?

Answer: To establish the actual name of the user's Web browser, you can use the

navigator.appName
and
navigator.userAgent
properties. The
userAgent
property is more reliable than
appName
because, for example, Firefox or Opera may return the string
"Netscape"
as the value of
navigator.appName
, reflecting earlier efforts to achieve better compatibility with (now extinct) Netscape Navigator. Note, however, that
navigator.userAgent
may be spoofed, too – that is, clients may substitute virtually any string for their
userAgent
. Therefore, whatever we deduce from either
appName
or
userAgent
should be taken with a grain of salt.

The code example below uses

navigator.userAgent
to implement browser detection. It also uses
navigator.appName
and
navigator.appVersion
as a last resort only, if the
userAgent
string has an "unexpected" format. In your browser, this code produces the following output:

And here is the source code that performed the browser detection:

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 15+, the true version is after "OPR/" 
if ((verOffset=nAgt.indexOf("OPR/"))!=-1) {
 browserName = "Opera";
 fullVersion = nAgt.substring(verOffset+4);
}
// In older Opera, the true version is after "Opera" or after "Version"
else 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>'
)

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