Google has begun auto-deleting new users' search data and location history on a rolling 18-month basis, CEO Sundar Pichai announced, as the tech giant moves to tighten privacy settings.

The tweak was introduced Wednesday and is the latest attempt by a big online firm to boost public trust after hefty fines were levied against Facebook and Google for privacy violations in recent years.

"We believe that products should keep your information for only as long as it's useful and helpful to you," Pichai said in a blog post, adding that the changes were designed to "keep less data by default."

When creating a new Google account, "your activity data will be automatically and continuously deleted after 18 months, rather than kept until you choose to delete it," he explained.

Current users can already opt in to auto-delete their data every three or 18 months -- a setting that has not changed, although existing users will be reminded of the option to do so.

Smartphone location technology has been in the spotlight as governments study or implement app-based initiatives to prevent the spread of the coronavirus, despite concerns over privacy and civil liberties.

Pinchai, also head of Google's parent company Alphabet, asserted that "privacy is at the heart of everything we do" in his blog post.

He detailed other changes including easier access to privacy settings within apps and to the more secure "incognito" mode.

New users of Google's subsidiary YouTube will also have their search data auto-deleted after 36 months, Pinchai said.