From a developer's perspective, you can use these tools for testing to reproduce how an app or Web page will render in different browsers as well as on different devices and platforms through the responsive design and built-in simulators. The best part is that you can do all of this without having to leave your browser!
Commonly referred to as the F12 Developer Tools, an homage to the keyboard shortcut that has launched the interface since earlier versions of Internet Explorer, the dev toolset in IE11 and Microsoft Edge has come a long way since its inception by offering a very handy group of monitors, debuggers, emulators, and on-the-fly compilers.
- Click on the More actions menu, represented by three dots and located in the upper right-hand corner of the browser window. When the drop-down menu appears, select the option labeled F12 Developer Tools.
- The development interface should now be displayed, typically at the bottom of the browser window. The following tools are available, each accessible by clicking on their respective tab heading or using the accompanying keyboard shortcut.
DOM Explorer: Allows you to edit stylesheets and HTML in the active page, rendering the modified results as you go. Utilizes IntelliSense functionality to autocomplete code where applicable. Keyboard shortcut: (CTRL+1)
Console: Provides the ability to submit debugging information including counters, timers, traces, and customized messages via an integrated API. Also, lets you inject code into an active Web page and modify the values assigned to individual variables in real time. Keyboard shortcut: (CTRL+2) Debugger: Lets you set breakpoints and debug your code while it executes, line by line if necessary. Keyboard shortcut: (CTRL+3)
Network: Lists each network request initiated by the browser during page load and execution including protocol details, content type, bandwidth usage, and much more. Keyboard shortcut: (CTRL+4)
Performance: Details frame rates, CPU utilization, and other performance-related metrics to help you speed up page load times and other activities. Keyboard shortcut: (CTRL+5)
Memory: Helps you isolate and correct potential memory leaks on the current Web page by displaying a memory usage timeline along with snapshots from different time intervals. Keyboard shortcut: (CTRL+6)
Emulation: Shows you how the active page would render in various resolutions and screen sizes, emulating smartphones, tablets, and other devices. Also provides the ability to modify the user agent and page orientation, as well as simulate different geolocations by entering a latitude and longitude. Keyboard shortcut: (CTRL+7)
- To display the Console while within any of the other tools click on the square button with a right bracket inside of it, located in the upper right-hand corner of the development tools interface.
- To undock, the developer tools interface so it becomes a separate window, click on the button represented by two cascading rectangles or use the following keyboard shortcut: CTRL+P.
You can place the tools back in their original location by pressing CTRL+P a second time.