How to uncover what Facebook knows about you

The social media behemoth is watching.

With nearly 3 billion monthly active users, Facebook can keep tabs on about a third of the world’s population. Whether you visit the social network daily (as 1.82 billion people do) or only log on to RSVP to events, you should be aware of how much of your personal data you’re giving to the site and the company behind it.

Facebook primarily uses your information to serve you more relevant targeted advertising. While some see this as uncomfortably intrusive, others accept the ads as the price they pay for the network’s free services and tools. Whatever you think about the ethics of this data collection, you should know just what the company is learning about you—and how you can control the flow of information. While this guide can help, there’s only so much you can do to protect your privacy—if you really want to stop Facebook from mining your data, your best bet is to delete your account.

Check the advertising preferences

When you created your Facebook account, you entered basic background information, including your name and email address. The site also prompted you to fill out your location, work and education history, and friends and relatives currently on Facebook. But by observing your behavior on its network, the tech company has gathered a lot more information about you and your habits.

One quick way of checking exactly what details Facebook knows—and limiting who else can access them—is to visit the settings page. (If you’d prefer to get there without a link, log into the site and click the downward-facing arrow on the far right end of the navigation bar across the top of the screen. From the drop-down menu, select Settings & Privacy and Settings.) Here, you can see the information you’ve given to the social network, and determine which of these details Facebook should be allowed to share with advertisers.

For example, click Your Facebook Information to remind yourself whether you’ve shared your relationship status and employer with Facebook. Hit Ads to see the topics the company thinks you enjoy and, from that page, select Ad Settings to see what information Facebook uses to serve you advertisements. To stop the company from showing you ads based on these details, click the categories under Manage Data Used to Show You Ads and turn the toggle switches off or click the Remove button next to a topic of interest.

This doesn’t require you to eliminate helpful details from your profile—you can share, say, your relationship status but block ads that target you because of it. If you’re uncomfortable giving this information to the social network, you can delete it. Facebook also offers a fuller explanation of ad preferences.

Even if Facebook isn’t selling your information to advertisers, it could still be collecting it. In addition to making ads more relevant, the company can put your data—everything from the make and model of your phone to your most frequently used apps—to work fixing bugs and improving the social network. You can delete some of this data completely by going to your Facebook profile page (click your name on the toolbar at the top of the Facebook web interface, then click Edit Profile and Edit Your About Info). You can’t erase everything, but you can delete details such as where you work and go to school. You may also want to check out the More drop-down menu, where you can unfollow pages and manage other things you’ve liked along the way.

Download your information

You’ll never find every last detail that Facebook knows—or thinks it knows—about you: Its secret algorithms make some educated assumptions about who you are based on your profile and your online activity. Facebook uses some of these assumptions put categorize people into groups that advertisers can target. It doesn’t really matter if these assumptions are always right, as long as they make a more efficient advertising platform overall. In 2016, the Washington Post published a report on 98 different data points Facebook associates with your identity. These include data pulled from other companies and services—like what year you bought your car and what type of credit card you carry.

However, Facebook isn’t a completely closed black box. In addition to checking your recent activity in the Activity Log (to access it, go back to the Your Facebook Information page and click Activity Log), you can download a trove of information, including comments you’ve left on other peoples’ pages and photos, and a history of your logins.

There were once third-party tools that sought to offer this information and predict how Facebook might track and interpret your data, like now-defunct website Stalkscan and Google Chrome extension Data Selfie. Now, you can just navigate to the Your Facebook Information page and click Download Your Information. You can select a date range, file format, and the quality of photos and other media included in that file.

Disable location and web tracking

Beyond the information you give up in your profile and the pattern of your clicks (from likes to photo comments), Facebook collects two other big pieces of data: your location (determined via your smartphone) and your activity elsewhere on the internet.

Letting Facebook’s phone app know where you are has some upsides. It enables you to check into places, search for interesting spots nearby, and even find your friends more easily. It also tells Facebook where you tend to hang out, allowing the service to be more precise about the ads it shows you.

If this makes you uncomfortable, you can turn off its ability to keep tabs on your whereabouts. On Android phones, open Settings, tap Apps and Notifications, Advanced, Permissions manager and Location. Then select the option to deny. On an iPhone, open Settings, tap Privacy, then Location Services, and find Facebook. Set “allow location access” to Never. Even with these precautions, Facebook still can keep tabs on you—for example, it will take note when your friends tag you.

The simple reason why Facebook tracks you around the internet should be clear by now: better advertising. Facebook can receive notifications when you spend time on specific webpages. In addition, the marketing platforms and sites to which Facebook sends your information can also send the social network their own carefully gleaned data about you (this explanation has more information about the practice—known as off-Facebook activity). What’s in this data? You can’t know exactly, beyond checking the Ads page we’ve already mentioned.

To prevent Facebook from following you around the web, go to, open the Ads page, find Ads Settings from the menu on the left, and select Ads shown off of Facebook. Turn the toggle switch to Not Allowed. You can also visit the Digital Advertising Alliance and specifically opt out of numerous cross-site tracking programs, including the one run by Facebook.

These days, Facebook takes more care to explain what type of user data it collects, but you still can’t reclaim all of your information—that’s something you sacrifice when you agree to sign up for the service. What you can do is be more aware of the types of information you reveal as you fill out your profile, react to your News Feed, and browse the web.

David Nield

David Nieldis a tech journalist from the UK who has been writing about gadgets and apps since way before the iPhone and Twitter were invented. When he's not busy doing that, he usually takes breaks from all things tech with long walks in the countryside.