We all know how hard to get our design right in Internet Explorer. Though there is developer tool available, it lacks some important features such as Live dom edit as in firebug or chrome developer tool. IE 11 fixed all such issues, have a look its features.
New user interface
In IE 11, F12 debugger tools redesigned as scrolling ribbon which is positioned at left side of the debugger panel. The UI style designed more like windows 8 model.
From this version we can see events attached to a element by just clicking on it. This will save huge time in debugging.Breadcrumb navigation,css intellinsense features also available.
This is new tool in developer tools which helps you to measure resoponsiveness of the page. It points out cpu usage of the page and ui performance issues if any. By clicking on a element it shows you how some actions or styles affects page rendering.
The tool allows you to take snapshots of your site or app's memory usage over a period of time allowing you to pinpoint which actions or areas of your app may be the root cause of the issue.
By changing the document mode to "Edge", a developer can force their site to render in the most recent standards mode supported by that version of IE and work to make the necessary standards-based changes to have their site render cross-browser. In addition, an informational link is provided directly in the tool which takes developers directly to modern.IE, an online resource which offers a scanner for common compatibility issues, virtual machines for the different versions of Internet Explorer, and best-practices for ensuring site compatibility in modern versions of IE.