What blocking actually does
When you block a person on Facebook, they lose the ability to see your profile, send you messages, find you in search, or see your posts in their feed. The block is one-way — they cannot see you, but you can still see their public activity if you want to. Facebook does not tell them they have been blocked; they will only know if they try to visit your profile or search for you and notice you have disappeared.
Blocking is different from unfriending. When you unfriend someone, they can still see your public posts and find your profile — they just cannot see your friends list or message you as easily. A block removes you from their view almost entirely. If your profile is set to private, an unfriended person sees even less, but a blocked person sees nothing.
Key Takeaways
- A blocked person cannot see your profile, posts, or messages, and Facebook does not notify them that you blocked them.
- Blocking is one-way — you can still see their public posts and activity, but they cannot see yours.
- If you block someone, any existing messages between you stay in your inbox, but they cannot send new ones.
- Unblocking someone later is possible, but they will not receive a notification that you have unblocked them either.
- Blocking is permanent until you choose to undo it; there is no automatic expiration or time limit.
What the blocked person can and cannot do
A blocked person cannot visit your profile, see your posts in their feed, or find you through the Facebook search bar. They cannot send you friend requests, messages, or see your comments on mutual friends' posts. If you comment on a public page or a mutual friend's post, the blocked person will not see your comment — it will be hidden from their view.
However, a blocked person can still see posts you made before the block if they are shared on a public page or in a group you both belong to. They cannot interact with those posts (like or comment), but they can see that the post exists. If you are both members of a Facebook group, they can see your group activity, though your profile link will not work for them.
Blocking does not remove you from their friends list retroactively — if they screenshot your profile or save messages before you block them, those records stay on their device. Facebook only prevents new contact and visibility going forward.
Your messages and conversation history
Messages you have already exchanged with a blocked person remain in your inbox. You can still read the old conversation, but the blocked person cannot send you new messages. If you open the conversation thread, you will see all previous messages intact. The blocked person's name may appear differently or show as unavailable, depending on your Facebook version.
If you unblock the person later, the old messages reappear for both of you, and they can resume sending you messages. Blocking does not delete the conversation history — it only stops new communication. If you want to erase the conversation entirely, you must delete the thread manually after blocking.
How to block someone on Facebook
On the Facebook app or website, visit the person's profile. Tap or click the three dots (more options) near their name or profile picture. Select "Block" from the menu. Facebook will ask you to confirm — tap "Block [Name]" to proceed. The block takes effect when ready.
You can also block someone from a message thread. Open the conversation, tap the person's name at the top, and select "Block." From a comment on a post, tap the three dots next to their name and choose "Block." All of these routes lead to the same result.
If you block someone before they send you a friend request, they cannot send one while blocked. If they try, Facebook will not deliver it. Once you unblock them, they can send a new request, but the old one will not reappear.
How to unblock someone
To unblock someone, go to your Facebook settings. On the app, tap the menu icon (three horizontal lines) and select "Settings & Privacy," then "Settings." Scroll to "Blocking" and tap it. You will see a list of people you have blocked. Find the person you want to unblock and tap "Unblock" next to their name.
On the website, click the downward arrow at the top right, select "Settings & Privacy," then "Settings." In the left menu, click "Blocking." Find the person and click "Unblock." Confirm the action. The unblock takes effect when ready, and the person can now see your profile and send you messages again.
Facebook does not notify the person that you have unblocked them. They will only know if they try to visit your profile again and find that it is now visible.
When blocking is not enough
Blocking prevents someone from contacting you through Facebook, but it does not stop them from creating a fake account to message you or viewing your profile through a different login. If someone is harassing you across multiple accounts, you can report each account to Facebook. Go to their profile, tap the three dots, and select "Report." Choose the reason (harassment, spam, or impersonation) and submit.
If the harassment continues or escalates to threats, take screenshots of the messages and report them to Facebook's safety team. You can also contact local law enforcement if you feel unsafe. Facebook takes reports of harassment, threats, and impersonation seriously and may disable accounts that violate their policies.
For ongoing harassment from someone you know, consider adjusting your privacy settings so only friends can message you or see your posts. You can also limit who can contact you by going to Settings > Privacy and changing your message settings.
Privacy and what others see
When you block someone, other people on Facebook do not see that you have done so. Your mutual friends will not receive a notification. However, if a mutual friend mentions you in a post or tags you, the blocked person will not see that tag or the post itself if it is on your profile.
If you block someone and then unblock them later, there is no record of the block visible to either of you or to mutual friends. Facebook keeps blocking actions private between you and the person involved. No one else can see your block list, and you cannot see anyone else's.
Frequently Asked Questions
Will the person know I blocked them?
Facebook does not send a notification when you block someone. They will only know if they try to visit your profile or search for you and notice you have disappeared. Some people figure it out by trying to message you or looking for your profile, but Facebook itself does not tell them.
Can a blocked person see my old posts?
If your posts are private or visible only to friends, they cannot see them. If you made posts public before blocking them, they may still see those posts if they are shared on a public page or group, but they cannot click your profile link or interact with the posts.
What happens if I block someone and then unfriend them?
Blocking already removes them from your friends list, so unfriending is unnecessary. If you unblock them later, they will not automatically be re-added as a friend — you will both have to send and accept a new friend request.
Can I block someone without them seeing that I viewed their profile?
Facebook does not show profile view notifications to most users, so they would not know you visited their profile before blocking them. However, if they have a feature enabled that shows who viewed their profile, they may have seen you before you blocked them.
If I block someone, will they see my comments on mutual friends' posts?
No. Your comments will be hidden from their view on mutual friends' posts. They will see that a comment exists, but they cannot see what you wrote or click your profile from that comment.