The only way they will know is if they actively search for you, stumble across your profile, or try to interact with you. For the vast majority of casual unblocks, the other person will never realize it happened.
Here's a step-by-step breakdown of what happens when you unblock someone on Facebook: if you unblock someone on facebook do they get notified
If you want to be friends again, you will need to send them a new friend request (and they will need to accept it). And yes, that friend request will generate a notification. The only way they will know is if
While there is no official “ping,” the person can figure it out on their own if they go looking. Here’s how: And yes, that friend request will generate a notification
When you unblock someone on Facebook, the person you unblocked will not receive a notification that you've unblocked them. However, there are some implications to consider: