How Facebook “Suggested Friends” Feature Actually Works

In a bid to get its users more connected, Facebook has a feature called “suggested friends” and in this guide, we’ll tell you how it actually works…

If you’ve been on Facebook during the last 12 months, you’ll have seen the “suggested friends” feature. You get a notification alert, you click on it, and Facebook has a suggested friend for you.

But how does this feature actually work? Do you have to know the person? Or is it just a random guess generated by Meta’s sprawling algorithm? More importantly, can you “game” this feature to appear
inside more people’s “suggested friends” list?

How Facebook’s “Suggested Friends” Feature Works

Officially, Meta’s stance on how Facebook’s suggested friends feature goes a little something like this: you must A) have friends in common, B) have similar and/or complimentary profile or network information, or C) have similar interests and/or activity on Facebook, either in groups or from being tagged in a photo and/or location.

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That’s the official explanation of how suggested friends works on Facebook but in my experience – granted, it’s pretty limited; I seldom use Facebook anymore – there is more to this feature than Facebook is letting on in its official description of how it works.

When Suggested Friends Gets Creepy

Here’s an example, from Reddit, of one guy’s experience with Facebook’s suggested friends.

As he points out in the post, Facebook is seemingly making connections between him and other people without actually having the requisite information to do so which leads to the obvious question: how is Facebook doing this?

One theory and I do think this is the most plausible, is that Facebook uses your search history on Facebook to make suggestions for suggested friends, so, in the above example, if the guy did a Facebook search for the girl he’d just been on a date with – regardless of whether it was a year or three years ago – Facebook will know and have this information.

An algorithm never forgets, all it does is grow and evolve, learning more and more about you. In this context, all the algorithm is doing is pulling information about a user from its bank of data and using it to create what it thinks are meaningful connections inside suggested friends.

Theories About How Facebook’s Suggested Friends Works

Phone Numbers

Another theory about how suggested friends works revolves around phone numbers. Say you give someone your phone number, perhaps you met in a bar or when on a date.

If that person uses their number on Facebook, Meta will continually scan their contacts list for new connections. Once it finds a new contact, in this case, you, Meta’s algorithm has your details and it will add you to the other person’s suggested friends list.

Canvas Fingerprinting

Another theory revolves around the idea of “canvas fingerprinting” which is a method for tracking users online without cookies. Now, this is pure speculation but a company the size of Meta is almost certainly using a raft of tracking technology to monitor its users, so it stands to reason that it might also be using its own proprietary version of canvas fingerprinting.

But what is canvas fingerprinting anyway? Here’s a quick overview:

Canvas fingerprinting gets its name because it instructs web browsers to draw a hidden image, and each computer produces a slightly different, unique image. Like a fingerprint. A creepy fingerprint that wants to follow you online.

Once your browser draws the hidden picture, the information is relayed to the website. It uses your unique image to assign a number to your computer and develop a user profile to better sell targeted ads. Canvas fingerprinting was invented in 2012, and a company called AddThis developed code used in 95 percent of the cases.

Gizmodo

If Facebook is using some kind of version of this technology, it could well use it to start making connections between two, disparate accounts. Again, this is just a theory – Meta has never confirmed this – although we do know that Facebook, like Google, does use fingerprinting techniques to track and analyze its users.

You Both Viewed One Another’s Profile

One of the simplest ways suggested friends might work relates to how you actually interact with Facebook. Here’s an example: say you randomly remember someone from school, so you do a Facebook search to see if they have a profile. If you find them and go onto their profile but do not add them, Facebook’s algorithm will make a note of this.

Now, say the person you looked for has the same idea: they remember you and then do the same thing, search for your profile, click on it, but they don’t add you. The algorithm will assume you’re both interested in one another, but are being shy or whatever, and set out to make the connection happen by adding you to their suggested friends list and vice versa.

For instance, prior to writing this article, based on a hunch, I decided to see if I could alter how suggested friends works by searching for and visiting a few profiles of people that I know but are not connected to on Facebook. I waited a few days and, sure enough, a few of them popped up in my suggested friends list.

Facebook is Spying On Your All The Time

There’s a popular belief that, by having Facebook installed on your phone, you’re being tracked 24/7, 365 days a year. This theory posits that Facebook uses your phone’s microphone to listen to you, your camera to spy on you, and your phone’s GPS to know where you are at all times, as well as when you interact with other Facebook users.

Facebook – sorry, Meta – has emphatically denied that it does this. But there are still thousands of reports online that suggest the contrary. I mean, check out this little ditty from one Reddit user:

Or, this one:

Of course, these are Reddit users we’re talking about here, so all bets are off when it comes to the legitimacy of these claims. But if we play devil’s advocate here, there might well be something going on – something that isn’t listed in Meta’s official stance on how it tracks and monitors its users.

I mean, this is Meta we’re talking about here, not some small startup. It almost certainly has exotic technologies employed on its platform that aren’t publicly known. Much of this can – and is – explained away as “just stuff the algorithm does” but an algorithm is only as good as the data set it is fed.

The bigger question here, then, is perhaps what technologies does Meta use to build up its data profiles? We know the ones it officially uses, but are there “other” less official technologies in place? My best guess would be that, yes, Meta does use exotic proprietary tracking and monitoring tech but we probably won’t know about them until the next Cambridge Analytica-style scandal drops.

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Richard Goodwin

Richard Goodwin has been working as a tech journalist for over 10 years. He is the editor and owner of KnowYourMobile.