UPDATE: Most of the services seem to be back online now. Leave a comment if you’re still having issues!
According to Downdetector, a number of Google services went offline earlier today, including YouTube, Gmail, and Google Docs. At present, the issue is still persisting. Users across the world have noted that the services are unavailable in their regions as well.


Google has not made an official statement about why this is occurring so far, but the problem appears to be a massive IoT DDoS attack against Google’s services. The search engine, however, is online at the moment. The company will likely answer this question after they are able to mitigate the issue.

In the past, IoT DDoS attacks have shut down other major services such as Amazon, using such tools as the Mirai Botnet. Even with DDoS protection services, it is difficult to defend against massive amounts of data being used against servers.
go to this site and check the status of Google services https://www.google.com/appsstatus#hl=en&v=status
all the services went down nearly for an hour