Facebook plans to add a dating service, chief executive Mark Zuckerberg says, marking the first time the world's largest social media network has actively tried to help people form romantic relationships.

Key points: Mark Zuckerberg says dating service "not just for hook-ups"

Mark Zuckerberg says dating service "not just for hook-ups" There are 200 million single people on Facebook

There are 200 million single people on Facebook Facebook chief also announces a new "clear history" privacy control

Shares of Match Group, the owner of popular dating app Tinder, fell more than 18 per cent on the news and was down 22 per cent at close.

Mr Zuckerberg told software developers at Facebook's annual F8 conference that a dating service would be a natural fit for a company that specialises in connecting people online.

"There are 200 million people on Facebook that list themselves as single, so clearly there's something to do here," Mr Zuckerberg said.

This is not (just) for hook-ups

Mr Zuckerberg said the new dating feature is "not just for hook-ups" but to build "meaningful, long-term relationships." That seemed a direct swipe at Tinder, which is still best known for hooking people up with people they find attractive by showing their photo, age and first name

It will be optional and will launch soon, he added, without giving a specific day.

A prototype displayed on screens at the F8 conference showed a heart shape at the top-right corner of the Facebook app.

Pressing on it will take people to their dating profile if they have set one up.

So how will this actually work?

The Facebook dating profile you'll create will be separate from your regular Facebook profile. It won't suggest your friends as people you might want to date, even if your 500-plus "friends" include random acquaintances - or crushes.

Your dating profile won't show up on your news feed or be visible to friends; it's only for others using the dating service.

After setting up a profile, you can browse events and groups based on location and interests. After you "unlock" an event you're attending or considering going to, you can view the profiles of others who have also unlocked that event.

Users can chat with each other through a private messaging feature that won't be connected to Facebook's other messaging services, Messenger or WhatsApp.

A dating service could increase the time people spend on Facebook and be a "big problem" for competitors, said James Cordwell, an analyst at Atlantic Equities.

"But the initial functionality looks relatively basic compared to those offered by Match's services, so the impact Facebook has on the dating space will be down to how well it executes in this area," Mr Cordwell said.

Sorry, this video has expired Mark Zuckerberg addresses Facebook privacy leak at a US congressional inquiry (Photo: Reuters/Aaron P. Bernstein)

The dating service is being built with privacy in mind, so that friends will not be able to see a person's dating profile, Mr Zuckerberg said.

Concerns about Facebook's handling of privacy have grown since the social network's admission in March that the data of millions of users was wrongly harvested by political consultancy Cambridge Analytica.

New 'clear history' feature coming

Mr Zuckerberg also said Facebook was building a new privacy control called "clear history" to allow users to delete browsing history.

"This feature will enable you to see the websites and apps that send us information when you use them, delete this information from your account, and turn off our ability to store it associated with your account going forward," the company said in a separate blog post.

Mr Zuckerberg compared the new tool to the option of clearing cookies in a browser, which he said can make parts of the user experience worse as users may have to reconfigure things.

Facebook said it would take a few months to build the update, adding the company would work with privacy advocates, academics, policymakers and regulators to get their input on the new approach.

Tech companies are under intense scrutiny about how they protect customer data after Facebook was embroiled in a huge scandal where millions of users' data was improperly accessed by a political consultancy.

"One thing I learned from my experience testifying in Congress is that I didn't have clear enough answers to some of the questions about data," Mr Zuckerberg wrote.

Mark Zuckerberg addresses Facebook's annual F8 developers conference in San Jose, California. ( Reuters: Stephen Lam )

Reuters