SAN FRANCISCO — Google Inc.’s Gmail service was knocked offline Tuesday in an outage that the company said affected a “majority” of its millions of e-mail users, including consumers who get Gmail for free and businesses that pay for a supported version for their employees.
The disruption, which lasted less than two hours, was a reminder of the growing dependence on Google’s technology. The free version of Gmail is the world’s third most popular e-mail program, with 149 million users worldwide in June. Gmail ranks behind the free e-mail services offered by Microsoft Corp. and Yahoo Inc., according to data from comScore Inc.
Google says only that Gmail is used by tens of millions of people.
Although occasional disruptions are common, widespread outages involving Google’s services are rare. They are becoming a bigger threat to Google as it tries to sell more of its services to businesses.
Businesses are increasingly leaning on Google’s services because they are delivered over the Internet instead of being managed in-house. That can save companies money and buy them more storage than they could otherwise afford. But many corporations are skeptical about outsourcing such critical tasks.
Google argues that Web-based services are more reliable than those handled in-house, but big outages such as Tuesday’s add another challenge to selling to reluctant businesses.
As usually happens with hiccups in popular Web-based services, the Gmail glitch touched off a flurry of posts to social-networking websites from frustrated Gmail users wondering whether others were having the same problem.
“Minute 30 of Gmail outage. The cities are in flames and people eating pets to survive. To future generations: we meant well,” one user commented.



