WhatsApp being a closed source app, owned and operated by Facebook, there’s not much you can do to protect your privacy from that angle. You can, however, limit the amount of data you expose to other WhatsApp users. These are all the privacy settings and tricks for WhatsApp you should be using.
Settings -> Account -> Privacy
- Last seen: nobody
- Profile photo: nobody
- About: nobody
- Status My contacts
- Read receipts: off (warning: read receipts are always sent for group chats, regardless of this setting)
- Groups: My contacts
- Live location: none
- (Optional: turn on fingerprint lock. Not necessary if you have secured your phone in other ways, including physically limiting others’ access to it.)
Settings -> Profile
- Remove profile picture
- Don’t use your full or real name
- (Optional: if you choose to keep your “About” section visible, you can write there that you don’t use WhatsApp and prefer Wire or Signal instead for communications.)
Bonus tips
- Settings -> Account -> Security
- Show security notifications: yes
- Settings -> Account -> Two-step verification
- Enable!
- Settings -> Account -> Notifications
- Use high priority notification: off
Let me know if there’s any other good ways for WhatsApp “hardening”!