Detect IE8 64bit in Javascript

Question

Hey there, I just wondered if there is a method to detect if the 64bit or 32bit Version of IE8 is running?

Because there are some major Bugs in the Facebook Javascript SDK which only occure in IE8x64...

Answer 1

According to this IEBlog post you should be able to read it from the browsers User-Agent string via navigator.userAgent:

Detecting 64-bit Internet Explorer

As machines with more than 4 gigabytes of RAM become more common, more and more users are running 64-bit versions of Windows. For compatibility with 3rd party add-ons, the 32-bit edition of Internet Explorer remains the default on 64-bit systems. However, in some cases it can be useful for websites to recognize when users are visiting using 64-bit systems—for instance, a site may want to know whether to offer a 64-bit executable download.

Tokens in the User-Agent string will enable you to determine whether or not the user is running a 64-bit version of Windows, and whether they are running the 64-bit edition of Internet Explorer.

64-bit IE on 64-bit Windows:

Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Win64; x64; Trident/4.0)

32-bit IE on 64-bit Windows:

Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; WOW64; Trident/4.0)

Incidentally, WOW64 stands for “Windows on Windows 64-bit.”

Answer 2

The User Agent string for a 64-bit IE browser will indicate that it's 'x64' or 'Win64' if it's a 64-bit browser.

http://blogs.msdn.com/b/ie/archive/2009/01/09/the-internet-explorer-8-user-agent-string-updated-edition.aspx

A 64-bit IE8 user agent string:

Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Win64; x64; Trident/4.0)

vs. a 32-bit

Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; WOW64; Trident/4.0)