Several Google services, including Gmail and Google Drive, experienced widespread disruption yesterday, with users complaining they were unable to access their files or send e-mails with attachments.
Affected users flocked to social media to complain about the outage at around 10am Singapore time.
The first reports came from users in the Asia-Pacific region, though the outage appeared to affect users around the world.
The outage lasted around four hours. At 2.13pm, Google posted an update on its G Suite Status Dashboard - which offers information on Google services - saying that the problems with Gmail and Google Drive had been resolved.
The tech giant also apologised for the inconvenience and said it would provide a more detailed analysis of the incident after completing an internal investigation.
Local smart living platform developer Habitap, which has been using G Suite apps for a couple of years, was one of the affected firms.
Chief executive Franklin Tang said his 30-odd employees "kept getting bounced out" of their e-mail app and could not forward their e-mails or download attachments from around 10am. The outage lasted till noon, but Gmail was still very slow after that, he said.
"As a company, we have been very complacent, thinking that Google will never have downtime. We now realise that when they have a service disruption, we are crippled," he said.
"Work basically ground to a halt because I had documents that I needed to send urgently and there was no way I could send them," he added.
Google posted on the G Suite Status Dashboard earlier at 10.53am to say that users were reporting "error messages, high latency, and/or other unexpected behaviour".
The disruption affected users of workplace G Suite accounts as well as those using personal Google accounts, although the reason for the outage remained unclear, and some users could still access Google Drive. Both Gmail and Google Drive have over a billion users each.
At the peak of the outage, monitoring site Downdetector received more than 1,000 reports from users having difficulty using Gmail and Google Drive, while Outage Report clocked more than 6,000 reports from affected users all around the world.
While Google did not confirm if its other services, such as Maps, were also affected, there were reports of glitches with photo uploads as well as error messages appearing in Google's YouTube video service.