Users of WhatsApp will be able to lock any particular chat on the service using their fingerprint, passcode, or face. Every other week, WhatsApp releases new tools or privacy updates while frequently developing new features. The fact that the instant messaging service is currently developing a new privacy feature that will enable users to lock their private chats within the app itself should not come as a surprise.
As each locked chat will require a unique passcode in the form of a fingerprint, face lock, or password to get through, the feature, which is still in testing, will add an additional layer of privacy and protection on WhatsApp. No one can access your locked chats until the passcode is mentioned, even if your WhatsApp platform is open and you are surrounded by other users.