If I block a contact in WhatsApp, will they know about it - briefly?
No, the contact will not be notified if you block them on WhatsApp. However, there are some signs that might indicate to them that they have been blocked, such as no longer seeing your profile picture or status updates.
If I block a contact in WhatsApp, will they know about it - in detail?
When you block a contact on WhatsApp, there are several implications regarding their awareness of the action.
Firstly, the blocked contact will not receive any notifications or alerts indicating that they have been blocked. They will continue to see your profile picture and status updates as usual, assuming these settings were previously public. However, they will no longer be able to send you messages, make calls, or view your last seen or online status.
Secondly, if the blocked contact tries to message you or call you, WhatsApp will not deliver those messages or connect the call. Instead, the sent messages will appear as a single tick (indicating they have left the device) but never turn into double ticks (indicating delivery). This could potentially alert them that something is amiss, but it won't explicitly state that they have been blocked.
Additionally, if you are part of a group chat with the blocked contact, they will still be able to see your messages within that group. However, you will not receive any messages from them in private or group conversations. If they try to add you to a new group, you will not receive the invitation.
In summary, while there are some subtle indications that could hint at being blocked, WhatsApp does not provide explicit notifications to users who have been blocked. The primary changes they will experience are the inability to communicate with you directly and the lack of delivery confirmation for messages.