Facebook rolls out tool to block off-Facebook data gathering

SAN FRANCISCO — Soon, you could get fewer familiar ads following you around the internet — or at least on Facebook.

Facebook is launching a long-promised tool that lets you limit what the social network can gather about you on outside websites and apps.

The company said Tuesday that it is adding a section where you can see the activity that Facebook tracks outside its service via its “like” buttons and other means. You can choose to turn off the tracking; otherwise, tracking will continue the same way it has been.

Formerly known as “clear history,” the tool will now go by the slightly clunkier moniker “off-Facebook activity.” The feature launches in South Korea, Ireland and Spain on Tuesday, consistent with Facebook’s tendency to launch features in smaller markets first. The company did not give a timeline for when it might expand it to the U.S. and other countries, only that it will be in “coming months.”

What you do off Facebook is among the many pieces of information that Facebook uses to target ads to people.

Blocking the tracking could mean fewer ads that seem familiar — for example, for a pair of shoes you decided not to buy, or a nonprofit you donated money to. But it won’t change the actual number of ads you’ll see on Facebook. Nor will it change how your actions on Facebook are used to show you ads.

Even if you turn off tracking, Facebook will still gather data on your off-Facebook activities. It will simply disconnect those activities from your Facebook profile. Facebook says businesses won’t know you clicked on their ad — but they’ll know that someone did.

So Facebook can still tell advertisers how well their ads are performing.

Jasmine Enberg, social media analyst at research firm eMarketer, said the tool is part of Facebook’s efforts to be clearer to users on how it tracks them and likely “an effort to stay one step ahead of regulators, in the U.S. and abroad.”