Tap and hold on to the message you want to delete on your phone. Select Remove when prompted. When asked to choose who will be removed from the group, tap Unsend or Send Later (depending on your settings). When asked whether you’re sure you want to remove it for them, confirm by tapping Yes.
In the messenger, “delete” erases the message in your thread but not the recipients’ versions. So removing a message or conversation from your inbox won’t remove it from your friend’s inbox. It isn’t possible to remove messages that have already been sent or received in a friend’s inbox.
Tap “Delete” on the app to erase a Facebook Messenger chat. To get rid of a discussion in the Facebook Messenger app, press and hold your finger on it until it begins to wiggle, then tap “Delete.” Once you’ve confirmed you wish to remove the conversation, it will be permanently removed from your account.
Before You Begin: Facebook keeps all of your deleted data for up to 90 days. If you try recovering messages after this time period, the chances of success are rather low. For further assistance, go to their Messenger Help Center.
Messenger keeps a complete history of all your back-and-forth conversations, stretching back years, unless you delete the history between yourself and another person.
