In select regions, Facebook offers a "Lock Profile" feature. This completely locks down your timeline so that anyone who is not your confirmed friend can only see a small preview of your profile picture and cover photo.
, and third-party apps cannot provide this functionality. Any app or website claiming otherwise is almost certainly a scam designed to steal your login credentials or install malware. facebook profile viewer
You can always see who liked, reacted to, commented on, or shared your posts. This isn’t passive viewing, but it’s official data Facebook provides. In select regions, Facebook offers a "Lock Profile" feature