Facebook’s Buddy ID feature allows users to find their friends on Facebook by syncing their phone contacts. When a user enables Buddy ID, Facebook will access their phone contacts and try to match the contacts to existing Facebook profiles. This allows users to quickly find and connect with friends who are already on Facebook without having to search for them or send individual friend requests.
How does Facebook access your contacts?
When you first enable Buddy ID in the Facebook app, you will be prompted to give Facebook permission to access your phone contacts. This allows Facebook to read your contact list and collect the names, phone numbers, and email addresses stored there.
Facebook says they use this contact information solely for the purpose of matching it against existing Facebook users in order to generate friend recommendations. The phone numbers and email addresses themselves are not retained by Facebook.
Matching contacts to Facebook profiles
Once Facebook has access to your contacts, their algorithms will match the contact information to existing Facebook users. Matches are made based on names, phone numbers, and email addresses.
For example, if you have “Alice Smith” listed in your phone’s contacts with the phone number 123-456-7890, Facebook will search its user base for any users that also have the name “Alice Smith” and phone number 123-456-7890 associated with their profiles. When a match is found, Facebook will recommend that contact as a friend for you to add.
Dealing with partial matches
In some cases, Facebook may find partial matches between your contacts and Facebook users. This could happen if the name or contact info doesn’t match exactly.
For example, your contact might be listed as “Al Smith” while the Facebook profile is under the name “Alice Smith”. Or you might have only a phone number or email address for a contact. In these cases, Facebook will still try to recommend possible profile matches, but the recommendations may be less accurate.
Connecting to matched friends
Once Facebook has recommended friends based on your contacts, you can review the suggestions on your Facebook Friend Recommendations page. For each recommended friend, you will see mutual friends listed (if any) as well as the source of the recommendation (e.g. phone contacts).
You can then choose to connect with the recommended friends by adding them as friends or sending a friend request. The friend request will be sent via Facebook as normal.
Opting out of Buddy ID
Using Facebook’s Buddy ID feature is optional. If you change your mind and no longer want your contacts used for friend recommendations, you can turn off Buddy ID at any time.
Here are the steps to disable Buddy ID:
- Open the Facebook app on your phone and tap the three-line “hamburger” menu icon.
- Scroll down and select “Settings & Privacy” then “Settings”
- Tap “Account Settings”
- Scroll down and tap “Sync Contacts”
- Toggle the “Sync Contacts” switch off
This will prevent Facebook from accessing your contacts moving forward. However, any matching to Facebook profiles that already occurred cannot be undone. You’ll need to manually unfriend any contacts that were automatically added if you no longer want them as Facebook friends.
Limiting contact access
When enabling Buddy ID, you have the option to limit which contact data Facebook can access. On Android, you can choose to only allow Facebook to access your contacts stored on Facebook. On iOS, you can select individual contacts or contact groups that Facebook is allowed to access.
Limiting access in this way reduces the contact data available for matching, but may be preferred if you only want Facebook to match against certain contacts.
Data Facebook collects
According to Facebook, here’s the contact data they collect when using Buddy ID:
- Name
- Phone numbers
- Email addresses
- User IDs associated with contacts (e.g. hashes of phone numbers)
Facebook states they use this data solely for friend recommendation purposes and do not retain the raw contact data after a match is made.
Is Buddy ID safe to use?
Facebook states that they take measures to protect the contact data used for Buddy ID:
- Contact data is not visible to anyone outside of Facebook
- Data is not used for advertising purposes
- Syncing contacts is optional and can be disabled
- Users must affirmatively give permission for Facebook to access contacts
However, some privacy advocates have raised concerns about Facebook’s history of data handling. Users must decide for themselves if they are comfortable providing their personal contact data to Facebook in order to use the convenience of auto friend-finding. Limiting the contact access on iOS or Android adds an extra level of control.
Pros of using Buddy ID
Here are some potential benefits of using Facebook’s Buddy ID feature:
- Finds Facebook friends automatically – no need to search or send individual friend requests
- Quickly connects you with existing friends already on Facebook
- Shows mutual friends in common as a form of social verification
- Prevents creation of duplicate accounts since it matches against existing profiles
For those new to Facebook or with many contacts not yet on the platform, Buddy ID can jumpstart your Facebook friend community.
Cons of using Buddy ID
Some drawbacks or concerns with Facebook’s Buddy ID include:
- Requires sharing potentially sensitive contact data with Facebook
- Matching can result in unintended friend connections
- No easy way to undo friend recommendations if unwanted
- May be less useful if most contacts are already Facebook friends
Users comfortable with Facebook accessing their contacts may find the pros outweigh the cons. But those wary of sharing data may want to avoid Buddy ID or strictly limit access.
Conclusion
Facebook’s Buddy ID feature allows for convenient automatic friend finding by syncing your phone contacts with existing Facebook profiles. Friend recommendations are made based on matching contact details like names, phone numbers, and email addresses. While the tool provides an easy way to quickly connect with Facebook friends, it requires sharing your contact data with Facebook which raises some privacy concerns. Users must decide if the benefits are worth enabling Buddy ID given Facebook’s history and access to your personal contacts.