MENLO PARK Facebook has spent eight years nudging its users to share everything they like and everything they do. Now, the company is betting it has enough data so that people can find whatever they want on Facebook. And on Tuesday, it unveiled a new tool to help them dig for it.
The tool, which the company calls Graph Search, is Facebook's most ambitious stab at overturning the Web search business ruled by its chief rival, Google. It is also an effort to elbow aside other Web services designed to unearth specific kinds of information, like LinkedIn for jobs, Match for dates and Yelp for restaurants.
Facebook has spent over a year honing Graph Search, said Mark Zuckerberg, the company's co-founder and chief executive, at an event at Facebook's headquarters introducing the new product. He said it would enable Facebook users to search their social network for people, places, photos and things that interest them.
That might include, Zuckerberg offered, Mexican restaurants in Palo Alto that his friends have "liked" on Facebook or checked into. It might be used to find a date, dentist or job, other Facebook executives said.
"Graph Search," Zuckerberg said, "is a completely new way to get information on Facebook."
Graph Search will be immediately available to a limited number of Facebook users in the "thousands," Zuckerberg said and gradually extended to the rest.
Every Internet platform company has been interested in conquering search.
But Facebook search differs from other search services because of the mountain of social data the company has collected over the years. It knows which parks your friends like to take their children to, or which pubs they like to visit, and who among their network is single and lives nearby.
The company is betting that its users are more eager to hear their friends' recommendations for a restaurant than advice from a professional food critic or from a stranger on Yelp.
Its search tool is based on the premise that the data within Facebook are enough and that its users will have little reason to venture outside its blue-walled garden. What they cannot find inside the garden, its search partner, Bing, a Microsoft product, will help them find on the Web.
For now, the Facebook tool will mine its users' pictures, likes and check-ins, but not their status updates. Graph Search, Zuckerberg explained, is aimed at answering questions based on the data contained in your social network, not serving you a list of links to other websites.
Say, for example, you are searching for a grocery store in Manhattan. You would type that question into a box on your Facebook page and the results would show stores your friends liked or where they had checked in.
It remains unclear how users will react to having others mine the data they share on Facebook. Zuckerberg took pains to reassure users that what they post would be found only if they wanted it to be found. Before the new search tool is available to them, he said, users will see this message: "Please take some time to review who can see your stuff."
Facebook tweaked its privacy controls last December.
Zuckerberg said Tuesday that initially, photos posted on Instagram, which Facebook owns, would not be part of the database of photos that can be searched. Nor would he specify how soon Graph Search would be available to those who log in using the Facebook app on their cellphones.
The search tool is plainly designed with an eye toward profits. If done right, said Brian Blau, an analyst with Gartner, it could offer marketers a more precise signal of a Web user's interests. "It's going to lend itself to advertising or other revenue-generating products that better matches what people are looking for," he said. "Advertisers are going to be able to better target what you're interested in. It's a much more meaningful search than keyword search."
News of the new search tool offered a modest lift to Facebook shares, which rose 2.7 percent to a close at $30.10 Tuesday. Google remained stable, with a share price of nearly $725.