Скачать или смотреть How to Unread Messages on Facebook Messenger - Full Guide

Facebook Messenger did not have a built-in feature to mark messages as "unread" once you have read them. However, you could manually simulate this by using some workarounds:

Marking as Unread on Desktop:

Open the Facebook website on your computer.
Click on the Messenger icon to open your messages.
Locate the conversation you want to mark as unread.
Hover your mouse over the conversation, and you should see a small gear icon (options menu) appear next to it.
Click the gear icon, and a menu will appear. Choose "Mark as Unread."
Archiving the Conversation:

You can archive the conversation you've read, which essentially hides it from your main inbox. When you receive a new message in the archived conversation, it will appear as unread.
Locate the conversation you want to archive.
Hover over the conversation, click the gear icon, and choose "Archive."


Additionally, keep in mind that your contacts may still be able to see if you have seen their messages if you've opened the conversation and read the messages before marking them as unread. This method is more for your own organization and does not affect the sender's awareness of your actions within the conversation.