Google announced on his Official Google Webmaster Blog that they added a new feature Fetch as Googlebot tool to the Google Webmaster Tools, that will allow you to see how Googlebot renders the page.
In the old Fetch as Googlebot feature, we can not see the output of HTML code of webpage but new feature enable you to see the output of code and HTML, and Google will show also a visual representation of what googlebot see your webpage. This new feature also shows you error on your webpage that prevent Googlebot to fetching and rendering everything on the page.
The Fetch as Google tool lets you see a page as Google sees it. This is particularly useful if you’re troubleshooting a page’s poor performance in search results.
Here is the new “fetch and render” button on the Fetch as Google feature:
When you have added a page to Fetch and Render, it will take few times to complete the process of rendering. After finishing it will show complete status with indicator. The indicator may show “partial” rendering, if resources are being blocked from Googlebot’s crawl. Either way, clicking on it will show you the rendering results.
This feature also allow you to specify the device type you want to fetch and render as, such as desktop, smartphone or other devices.
Here is a desktop preview of render a webpage. See below :
Fetching shows you the code, HTML, etc, while rendering shows you the results as a web page visualization.