Where to find the block button on the app you use
The block feature lives in a different place on each messaging app, but the principle is the same: you find the conversation or contact, open a menu, and select block. The person you block cannot send you messages, see when you are online, or view your profile — though the exact restrictions depend on the app.
On iMessage (Apple's built-in messaging for iPhone, iPad, and Mac), open the conversation thread with the person you want to block. Tap the person's name or number at the top of the screen, scroll down, and tap "Block this Caller." On a Mac, right-click the conversation and select "Block" from the menu. The person will not see a notification that you blocked them, but if they try to message you, their message will not go through.
On Android's default Messages app, open the conversation, tap the three-dot menu at the top right, and select "Block." If you use a different Android messaging app (like Google Messages), the steps are similar but the menu location may differ — look for a three-dot menu or long-press the conversation name.
On WhatsApp, open the chat with the person, tap their name at the top, scroll to the bottom, and tap "Block Contact." On Facebook Messenger, open the conversation, tap the person's name at the top, scroll down, and select "Block." On Instagram Direct Messages, swipe left on the conversation (iPhone) or long-press it (Android), then tap "Block."
Key Takeaways
- Every major messaging app has a block feature, usually found by opening the conversation and tapping the person's name or a menu button.
- When you block someone, they cannot send you new messages, but old messages from before the block remain in your chat history unless you delete them separately.
- The person you block will not receive a notification that you blocked them, but they may figure it out if their messages stop going through.
- Blocking is different from muting: a muted conversation still receives messages, but you see no notifications.
- If you change your mind, you can unblock the person through the same menu where you found the block option.
What happens after you block someone
Once you block a contact, that person's new messages will not reach your phone or computer. If they try to send you a message on the app where you blocked them, the message will either fail to send or sit in their outbox with no delivery confirmation. They will not see a message saying "you are blocked" — instead, their message straightforward will not go through, and they may assume you are not responding.
The blocked person can still see your profile picture and status on some apps (like WhatsApp) unless you change your privacy settings separately. Blocking does not delete old messages from that person — those remain in your chat history. If you want to erase the conversation entirely, you must delete it manually after blocking.
On most apps, the blocked person can still call you unless you also block calls. WhatsApp, for example, blocks both messages and calls when you block a contact, but on iMessage you may need to block the caller separately if you want to prevent phone calls.
Blocking versus muting and reporting
Blocking is not the same as muting. When you mute a conversation, messages still arrive on your phone, but you receive no notifications — the chat sits silently in your message list. Muting is useful if someone is not harassing you but you straightforward do not want constant alerts. You can mute a conversation for an hour, a day, or indefinitely, and unmute it anytime.
If someone is sending threatening, abusive, or unwanted sexual messages, blocking alone may not be enough. Most messaging apps also have a report feature that sends the conversation to the app's safety team. On WhatsApp, you can block and report in one action by tapping the person's name, scrolling down, and selecting "Block and Report." On Instagram, tap the person's name, select "Report," and choose the reason. Reporting helps the app identify patterns of abuse and may result in the person's account being suspended or removed.
If the harassment is severe or involves threats, save screenshots of the messages and report them to local police as well. Messaging apps keep records that can be used as evidence.
How to block someone you have not messaged yet
You can block a contact even if you have never exchanged messages with them. This is useful if someone has your phone number or username and you want to prevent them from contacting you in the first place.
On iMessage, go to your Contacts app, find the person, tap "Edit," scroll down, and tap "Block this Caller." On WhatsApp, open your contacts list, find the person, tap their name, and select "Block Contact." On Android Messages, you may need to create a conversation with the person first before the block option appears — open a new message, type their number, and then block from the conversation screen.
If you block someone before they message you, they will not know you blocked them unless they try to contact you and notice their messages are not going through.
Unblocking and what the other person sees
If you change your mind, you can unblock someone at any time. The process is the same as blocking: open the conversation or contact, tap their name, and select "Unblock." Once unblocked, that person can message you again, and you will receive their messages normally.
When you unblock someone, they do not receive a notification that you unblocked them. They will not know unless they try to message you and see that their message goes through. Old messages from before you blocked them will still be in your chat history.
Unblocking does not restore deleted conversations. If you deleted the chat while the person was blocked, you will start fresh with an empty conversation thread once you unblock them.
Blocking across multiple devices
If you use the same messaging app on multiple devices — for example, WhatsApp on both your phone and tablet, or iMessage on your iPhone and Mac — blocking on one device usually blocks the person across all your devices. This is because the block is tied to your account, not the individual device.
However, some apps handle this differently. Check your app's settings to confirm. On WhatsApp, go to Settings > Account > Privacy to see your blocked contacts list, and any blocks you make will sync across your devices. On iMessage, blocks sync automatically if you are signed into the same Apple ID on all devices.
If you use different messaging apps on different devices, you will need to block the person separately on each app. For example, blocking someone on WhatsApp does not block them on Instagram Messenger.
When blocking does not work and what to do instead
Blocking works well for most situations, but it has limits. If someone creates a new account or uses a different phone number, they can contact you again. If the harassment is severe or ongoing, blocking alone may not solve the problem.
If someone keeps contacting you through new accounts or numbers, document each instance with screenshots. Report the pattern to the app's support team — most apps have abuse reporting features specifically for this. You can also block the new accounts as they appear.
If the person is harassing you in person or through other channels (email, social media, phone calls), blocking on one messaging app will not stop that. You may need to involve local police, especially if the behavior includes threats or stalking. Keep records of all contact attempts across all platforms.
Frequently Asked Questions
Can someone tell if I blocked them?
They will not receive a notification, but they may figure it out if their messages stop going through and you do not respond. On some apps, they might notice your profile picture or status is no longer visible. The only way to be certain is if they try to message you and see an error.
Will the person see my old messages after I block them?
No. Once you block someone, they cannot see any of your messages — old or new. However, you can still see their old messages in your chat history unless you delete the conversation.
If I block someone on WhatsApp, are they also blocked on Instagram?
No. Each app has its own block list. You must block the person separately on each messaging platform if you want to block them everywhere.
Can I block someone without deleting the conversation?
Yes. Blocking and deleting are separate actions. You can block someone and keep the old conversation in your chat history, or delete it later. If you unblock them, the old messages will still be there.
What if someone is harassing me through multiple accounts?
Block each new account as it appears and report the pattern to the app's support team. Save screenshots of the harassment. If it continues or involves threats, contact local police and provide them with the documentation.