These tools are more dangerous. They ask you to "Login with Facebook to verify your age." You are presented with a fake login page (a phishing site). When you enter your email and password, the attacker now has full access to your real Facebook account.
Result: They will spam your friends, change your password, or sell your login details on the dark web. Facebook Anonymous Viewer
Before you continue searching for a way to view someone’s Facebook anonymously, consider the ethics and laws at play. These tools are more dangerous
Many “viewer” sites require a “one-time $1 verification” to prove you’re not a bot. In fine print (often not visible), you agree to a $49.99 monthly subscription. Victims report recurring charges for months. change your password