Browser detection through JavaScript – Navigator Object

Getting client (browser) details is very easy through JavaScript. Client name, version, codename and the platform used are available through the navigator object and its properties. (The navigator object was named after Netscape Navigator).

• navigator.appName – Gives the name of the browser (application Name)
• navigator.appVersion – Gives the browser version (application Version)
• navigator.appCodeName – Gives the browser codename (application CodeName)
• navigator.platform – Gives the platform on which the browser is running

Because of browser incompatibility issue in DHTML, some web developers make two versions of their site, one that is compatible with Internet Explorer and the other that contains Netscape Navigator specific code. These developers use a browser detection script to transfer the visitor to the respective site.

We’ll concentrate only on Internet Explorer and Netscape Navigator since they are the most prominent browsers on the Internet.

To automatically transfer the visitor, we have to take the help of location property of the window object. Let’s look at the code.

<SCRIPT LANGUAGE="JavaScript" TYPE="TEXT/JAVASCRIPT">
<!--

var bname = navigator.appName;
if (bname == "Microsoft Internet Explorer")
   {
   window.location="explorer_version.html";
   }
else
   {
   window.location="netscape_version.html";
   }

//-->
</SCRIPT>

Deconstruction of the browser detection script

The browser name is obtained through navigator.appName and is stored in variable bname. Using an if statement we check the value of this variable. If it’s “Microsoft Internet Explorer”, we transfer the visitor to explorer_version.html else, the visitor is taken to netscape_version.html. Note that window.location takes a URL as value.

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