Once you know how Facebook selects your suggested friends, you'll never be the same.

Have you ever wondered how Facebook knew to suggest you add that dude you went on one date with four months ago? How it knew to suggest your ex’s new girlfriend even though you had no mutual friends?

You are not alone.

There are several sites where people have asked the question: “How does Facebook choose its suggested friends?”

The question was posed to members of a Reddit thread and their theoretical answers are making us regret every stalk we’ve ever made.


Congratulations! You’re being Facebook stalked! 

“I think if people look you up on Facebook then it starts suggesting them to you,” one user said.

“I had a situation like this with a girl from college. She started appearing in my suggested friends. We have no mutual friends, don’t live near each other and I didn’t have anything about college on my Facebook but she still was showing up there.”

Uh oh.

You’ve got their number.

“If their number is in your phone, and they have their number linked to their account, they might show up as suggested friends. Has happened to me a few times.”


Metadata mates.

“FB may use other things, such as various 3rd party cookies, macromedia cookies, and even such creepy things as Canvas fingerprinting.”

Canvas fingerprinting is not a fun holiday idea to do with the kids but a technique browsers can use to track online users as they move between sites.

The dating app link.

“I had my Facebook linked to my OkCupid to get pictures and FB started suggesting I friend all the guys I had been messaging. ”

Email. Remember that ol’ guy?

“Lately, this girl I was in a study group with TWO YEARS AGO and only ever talked to through email has been popping up pretty high on my suggestions.”

You've Got Mail is essentially desktop Tinder. Source: Screenshot/Warner Bros.

The Instagram connection.

"I researched this a few months ago and from what I gather, FB knows the websites you visit/are members of and can suggest people with similar internet histories? Which makes sense to me because a lot of people I follow on Instagram, but aren't friends with on Facebook (or even have mutual friends with) pop up frequently."

And... the impossible suggestions.

"I met a girl at the club last night. We had a pretty short conversation. I didn't even get her real name. Just a nickname. The next morning when I first opened my FB she popped up as a friend suggestion."

We don't have an official answer as there seems to be some ~ secrecy ~ around it but most sources say it makes suggestions off mutual friends, shared networks and profile information like work and education.

Even a user who posed it within the "Facebook Help Centre" was given a jumbled answer.

We'll take our theories, thank you.