How to block someone on Facebook Messenger
Open Messenger and find the conversation with the person you want to block. Tap and hold on their name at the top of the chat (on mobile) or right-click it (on desktop). Select "Block" from the menu that appears. Facebook will ask you to confirm — tap "Block" again. The person can no longer message you, see when you're online, or find your profile in search.
Once blocked, the conversation stays in your message list but appears grayed out. You won't see their messages, and they won't see yours. If you change your mind later, you can unblock them the same way: find their name, tap and hold, and select "Unblock".
Key Takeaways
- Blocking someone on Messenger prevents them from sending you messages, seeing your online status, or finding your profile in search.
- The block happens when ready — the person does not receive a notification that you blocked them, but they will notice they cannot message you.
- Blocked conversations stay in your message list but appear grayed out, and you can unblock someone at any time if you change your mind.
- Blocking is different from muting: muting silences notifications from someone without preventing them from messaging you.
- If someone is harassing you, blocking is a first step, but you can also report the conversation to Facebook for review.
What happens when you block someone
The person you block cannot send you new messages. Any messages they try to send will fail on their end — they'll see an error or the message will appear to send but won't reach you. They also cannot see your profile picture, status, or when you're online. If they search for your name, your profile won't show up in their results.
The blocked person does not receive a notification saying "you've been blocked." However, they will figure it out quickly when their messages fail to send and they can't find your profile. There is no way to block someone silently.
Blocking versus muting and other privacy controls
Muting is different from blocking. When you mute someone, they can still message you, but you won't get notifications. Their messages sit in your inbox, and you can read them whenever you want. Mute is useful if someone messages too often but you don't want to cut off contact entirely. To mute, tap and hold their name and select "Mute notifications."
Restricting is a middle ground. A restricted person can message you, but their messages go to a separate "Message Requests" folder instead of your main inbox. You see them only if you check that folder. Restrict is useful if you want to keep someone at arm's length without the finality of a block.
If someone is sending unwanted messages repeatedly, blocking is stronger than muting or restricting because it stops the messages entirely. If you just want fewer notifications from someone you trust, muting is gentler.
Blocking on mobile versus desktop
The steps are nearly identical on iPhone, Android, and desktop, but the exact taps differ slightly. On iPhone or Android, open Messenger, find the conversation, and tap and hold the person's name at the top. On desktop, right-click their name instead. Both lead to the same menu with a "Block" option.
After you block someone, the change syncs across all your devices within seconds. If you block someone on your phone, they're blocked on your desktop too, and vice versa.
Unblocking someone and what they see
To unblock someone, go to your Messenger settings, select "People," then "Blocked." Find the person's name and tap "Unblock." They can now message you again, and you'll see their messages in your inbox as normal.
When you unblock someone, they do not get a notification. They won't know you unblocked them unless they try to message you and it works. The old conversation history remains in your chat list, and you can see all the messages from before you blocked them.
What to do if someone is harassing you
Blocking stops the messages, but if someone is harassing you, you can also report them to Facebook. Open the conversation (or the grayed-out blocked conversation), tap the three dots or menu icon, and select "Report." Choose what kind of report it is — harassment, spam, or another category — and Facebook will review it.
Reports are confidential. The person you report does not see your name or know that you reported them. Facebook may warn them, restrict their account, or take no action depending on what they find. If the harassment is severe or involves threats, you can also contact local police.
Blocking does not hide past messages or shared content
Blocking someone stops new messages but does not erase old ones. If you and the blocked person shared photos, files, or links before you blocked them, those files remain accessible to both of you. Blocking does not delete the conversation history on either side.
If you want to remove a conversation entirely, you can delete it separately. Tap and hold the conversation and select "Delete." This removes it from your inbox but does not affect the other person's copy of the conversation.
Frequently Asked Questions
Can someone tell if I blocked them?
They don't get a notification, but they'll figure it out when their messages fail to send and they can't find your profile. There's no way to block silently. If you want to avoid the awkwardness, you could mute or restrict them instead, which they're less likely to notice.
What if I blocked someone by accident?
Go to your Messenger settings, select "People," then "Blocked," find their name, and tap "Unblock." They can message you again when ready. The old conversation history is still there.
If I block someone, do they see our old messages?
Yes. Blocking stops new messages but doesn't erase the past. They can still see all the messages you sent before you blocked them, and so can you. If you want to hide old messages, you have to delete the conversation separately.
Does blocking on Messenger also block them on Facebook?
No. Blocking on Messenger only affects Messenger. They can still see your Facebook profile, comment on your posts, and send you friend requests. To block them on Facebook itself, you need to block them separately from your Facebook settings.
Can I block someone without them knowing I'm online?
Blocking prevents them from seeing your online status going forward, but if they saw you online before you blocked them, that's already happened. Blocking is not retroactive. If you want to hide your online status from someone without blocking, you can turn off "Active Status" in your Messenger settings.