Internet Explorer 11 and “Enterprise Mode”

64px-Internet_Explorer_7_Logo“Our application only works on IE8”

was the refrain from a customer recently.  We just finished deploying Internet Explorer 11, and it was suddenly realised that the application had issues.

So doing some research, IE11 Enterprise Mode looks much better than setting IE Compatibility Mode via a X-UA-Compatible tab (blogged about that here).

The advantages of IE11 Enterprise Mode are as follows:

  • User agent string differences. Many legacy Web apps use browser detection, not today’s best practice of feature detection. By replicating the original Internet Explorer 8 user agent string, Enterprise Mode works for sites that fail if they can’t recognize IE8 as the browser.
  • ActiveX controls and other binaries. Some ActiveX controls silently fail if they query the browser version and get a response they don’t expect, so Enterprise Mode appeases these by mimicking IE8’s responses. In testing, customers report that many of these ActiveX controls “just work” in Enterprise Mode.
  • Deprecated functionality. Internet Explorer 8 still contained some vestiges of proprietary functionality, such as CSS Expressions which was used to place objects dynamically on a page. This functionality was removed in later versions of Internet Explorer, but some legacy Web apps used this to place buttons and other elements. Enterprise Mode brings back some deprecated features, including CSS Expressions.
  • Pre-caching and pre-rendering. Many modern browsers like Internet Explorer 11 pre-cache and pre-render pages, to make browsing more fluid. When you click on a pre-cached link, one tab disappears while the pre-rendered content tab appears in its place. To a legacy navigation controls, this behavior is confusing—so Enterprise Mode turns it off.

    (content courtesy of Microsoft’s IE Blog)

References: