Page Inspector in Visual Studio 2012 is a web development tool with an integrated browser. Select any element in the integrated browser, and Page Inspector instantly highlights the element's source and CSS. You can browse any MVC view, quickly find the sources of rendered markup, and use browser tools right within the Visual Studio environment.
Page Inspector is bundled with Microsoft Web Developer Tools. The latest version is 1.3. To check which version you have, run Visual Studio and select About Microsoft Visual Studio from the Help menu.
By default, Page Inspector is docked as a window on the left side of the Visual Studio environment. If you prefer, you can dock it elsewhere, or undock the window. See How to: Arrange and Dock Windows.
The top pane of the Page Inspector window shows the current page in a browser window. The bottom pane shows the page in HTML markup, along with some tabs that let you inspect different aspects of the page. The bottom pane is similar to the F12 Developer Tools in Internet Explorer.