When SPDY is available for a site, does Googlebot use it? If so, sites which are SPDY enabled would appear faster to Googlebot.
No, Googlebot doesn't use SPDY. SPDY was optimized for browsers, where things like pipelining & HTTP request headers are bottlenecks. These things generally aren't issues when crawling the web.
That said, SPDY may have some benefit in saving the server some work (it can serve multiple URLs with one request/response), so I wouldn't say that it's completely out of the question, but it's not used at the moment.
Do you have a source for this information?– DD.Dec 17, 2014 at 15:11
7John Mueller works for Google. This is info from inside the Googleplex. Dec 17, 2014 at 15:31
2I ended up talking with someone from the Googlebot team about this. At Google, we don't have these things documented (the list of things Googlebot doesn't do it pretty big), so I can't really point to anything as a reference. Dec 18, 2014 at 9:45
2With regards to potential future functionality, this kind of thing is something they would definitely consider, if they can see that it would have a significant impact. For example, if they see many servers that are overloaded with requests, where combining requests could allow better crawling, then maybe this would be an option. On the other hand, if it's only an option on servers that are already well-crawled, then it probably doesn't make that much sense. Dec 18, 2014 at 9:47