Popular Google services including Gmail, Docs and Drive were down for many users around the world on Thursday, but were restored after a few hours, the US technology giant said.
"We apologize for the inconvenience and thank you for your patience and continued support," the company said.
"System reliability is a top priority at Google. We are making continuous improvements to make our systems better."
Frustrated customers in countries including Australia, Japan, France and the United States complained online of the outage, and tracking website DownDetector reported Google services were down in every continent.
"Anyone else having issues with @gmail in Australia?" one person tweeted.
Another Twitter user, in Brooklyn, New York, wrote: "Nearly 16 years in and this is the first time I can remember Gmail being completely down."
Google's @Gmail Twitter feed replied to the posts with: "Thanks for reporting. We are aware of a service disruption at the moment."
The G Suite Dashboard tracking outages in Google's services showed it was working on the issue, and had it fully resolved in under six hours.
As well as English, the Gmail Twitter feed replied to people in French, Japanese, Portuguese and German.