Google has announced a new tool that enables users to see what information the internet firm keeps about their activities on Gmail, Reader, YouTube and other accounts.
The tool summarises data kept about the use of more than 20 of the firm's services and provides links to enable users to control personal privacy settings.
Google Dashboard follows on from similar tools introduced earlier this year to allow users to see the profile of interests Google is building up about them in order to serve targeted advertising.
"The scale and level of detail of the Dashboard is unprecedented, and we're delighted to be the first internet company to offer this and we hope it will become the standard," the post said.
Only information shared with Google while logged into its services is shown by the Dashboard, enabling Google account holders to change settings and delete data.
Privacy campaigners have welcomed Google Dashboard and called on the rest of the internet-services based industry to take a similar line to solve some of the challenges to privacy.
But Dashboard does not include information Google records without identifying accounts of users, such as server logs containing details of searches, web browser types and computer IP addresses.
Search data remains contentious between Google and European data protection officials who want to limit retention of such data to six months instead of Google's policy of nine.