Google announced on Webmaster Central Blog, Google Webmaster tools provides Webmasters with the results of Googlebot attempting to fetch their pages. They will try to find all the external files involved, include CSS, JavaScript files and images, as well as other files that might be indirectly embedded through the CSS or JavaScript. Fetch as Googlebot tool to just see an output of code and HTML but Google will show a visual representation of what Googlebot sees.
You can find the Fetch as Google feature in the Crawl section of Google Webmaster Tools. Then, submitting a URL with “Fetch and Render,” that will take a few minutes and show you a status complete indicator. Once it’s ready, just click on the response row to see the results.
You can specify the device type you want to Fetch and Render as, like desktop, smartphone or other devices. The following results show you the how the desktop and mobile version may look and also notice the tabs for both “fetching” and “rendering.”
Here is a Desktop sample:
Here is a Mobile sample: