The technical feat came thanks to a "party mode" that the company launched as part of its updated Android app for the social network. It was one of several improvements to Google+ that the company publicized at the conference that show Google is still working to lure users away from Facebook.

Google+ now hosts 250 million accounts and 150 million monthly active users, the company said Wednesday. Facebook boasts more than 900 million monthly active users.

Gundotra said users now spend an average of 12 minutes a day in the Google+ "stream," up from just nine minutes several months ago. But third-party studies have indicated Google has a long way to go. One released in February said users spent six to seven hours per month on Facebook, versus three minutes per month on Google+.

At Google I/O, Google launched a tablet-specific version of Google+ that will ship with its in-house tablet offering, the Nexus 7. The app is visually rich, with the photos that accompany popular posts displayed larger to make them easier to find. It is also the introductory platform for Events, a set of features that includes the party mode. In party mode, Google+ automatically clusters users' photos from the same event and orders them chronologically.

Events, which will reach iOS and Android smartphone users through an update, also includes an event invitation capability with visually elaborate templates for animated invitations. A Google+ member who creates the invitation can invite friends who aren't users.