Google Search Console – you don’t see what you get.
Life tended to get easy with the first outcome of WYSIWYG – technology: no suprises when seeing the rendered result of the work. With this premise we consulte Google every day to get a sense of how it works under the hood when it comes to crawling and indexing our web pages.
Fetch as Google
The part of the site the moment DOM is ready
Same part of the site 5 seconds later – you see the change?
This is what „Fetch as Google“ sees
This is what Google really puts in the index – see the difference?
We sum up
„Fetch as Google“ generates a screenshot the minute the DOM is ready. Everything that has been rendered until then, will come with the screenshot. But content that appears just seconds later, maybe because there was a slow server delivering it, will not be visible with the screenshot.
The more important indexing however, will take care of delayed content because it obviously takes care of any delay caused by setTimeout or asynchronous AJAX content. Here you will find what the screenshot does not unveils.
There is this and others signals from Google that they do not want you to see too munch from what they do and how it works. You mainly get some hints that may change their meaning down the road. So take care, because when it comes to Google, WYSINWYG*.
* WYSINWYG What You See Is Not What You Get