On your phone, you can turn on the chat lock feature to protect your personal chats with a password. To read or send messages, you’ll need to unlock the chats using device authentication, such as your phone passcode, Face ID or fingerprint.
These locked chats will be kept separate from your other chats in a ‘Locked Chats’ folder. The notifications for the locked chats will appear as “WhatsApp: 1 new message”. In order to keep the media safe, you’ll have to turn the chat lock off to save the media to your phone gallery.
Disappearing messages are another safety feature included in WhatsApp. With disappearing messages, you can control which messages stick around and for how long. You can set up disappearing messages after you have sent them.
By customizing the last seen online, you can decide your privacy settings to choose who can see when you are online and when you last used WhatsApp.