Google Drive accounts with five gigabytes of storage were available free at drive.google.com and upgrades to more space on servers in the California company's data centers were available at rates set by size and country.
"The model is really designed at the core to help people live their lives in the cloud," Google vice president for Chrome and Apps Sundar Pichai said on a conference call with reporters.
"Google Drive is something we see as central to the online experience at Google."
Google Drive software has been tailored for Windows and Macintosh computers as well as smartphones or tablets powered by Google-backed Android software.
A version tailored for Apple mobile gadgets will be released soon, according to Pichai.
"We want to make sure that all our users' data are available where ever they are," Pichai said.
Google Drive data can be reached from various devices, and deleting it from one deletes it from all. Scanned letters can be saved. Fax messages can be sent or received at Drive.