Facebook has overhauled its internal search engine to allow members to easily search through their friends' profiles.
Graph Search, unveiled at an event in Palo Alto, California, initially allows Facebook's one billion members to search the social network's vast database of people, photos, places and interests.
Most types of information members post is not yet indexed, but Mr Zuckerberg said engineers were working to expand it to other data such as Likes and events.
He emphasised the system did not allow members to search the web outside Facebook, quashing speculation before the event that it aimed to compete with Google more directly.
Graph Search allows Facebook members to query Facebook using natural language rather than keywords. Mr Zuckerberg said its creation had been really hard technical challenge for engineers that has been in development for more than a year.
Facebook executives emphasised that Graph Search complies with members' existing privacy settings. For instance, if someone has set a photo to friends only it will not appear results of a search for photos of friends of friends by a member who is not their friend.
Hiding material from Timeline, the feature that displays Facebook members' posts on their profile, will not stop them appearing in search results, however.
We're just going to keep educating users about that, said Tom Stocky, a senior member of the engineering team behind Graph Search and former Google executive.
He had said Graph Search was particularly potentially useful for dating. A search for male friends of friends who are single who live in San Francisco and are Indian would return a list of potential dates for a female friend from India who was new in town, he said.
