Google's John Mueller announced in a Google+ hangout that GoogleBot will soon be able to crawl web pages only accessible over HTTP2. Currently, GoogleBot cannot crawl HTTP2, the next version of HTTP, web pages.
He said this at the 3 minute mark into the video:
At the moment, GoogleBot doesn't support HTTP2 only crawling. So if you can only access your site via HTTP2, that is the next version of HTTP, then we would not be able to crawl that properly. We are working on that, I suspect it will be ready by the end of this year, maybe early next year, some time around that.One of the big advantages of HTTP2 is that you can bundle requests, so if you are looking at a page, it has a bunch of embedded images, CSS, JavaScript files, those things, theoretically, you can do one request for all those files...
Here is the video embed:
Forum discussion at Google+.
