Your phone notifications show a preview of new messages
Even when your phone is locked, new messages are previewed on your locked screen and anyone near your phone can read them. To disable this feature:
iPhone: WhatsApp settings > Notifications > Show Preview – and turn it off.
Android: WhatsApp settings > Notifications > Pop up notification > No pop up
Automatically saving images and videos that you receive
If you find that you’ve been running out of storage space frequently, check whether your phone is automatically saving all the images and videos which you receive through WhatsApp. You can change the settings so that you can choose to save only the stuff you want.
iPhone: WhatsApp settings > Chats > Save to Camera Roll and turn it off.
Android: WhatsApp settings > Data usage > Media auto download
Sending compromising photos or videos
When you send a message, photo or video on WhatsApp, the receiver will have a copy. Even if you’re careful about who you send them to, these can easily be forwarded to an infinite number of people instantly. Before you decide to share something, ask yourself if you want others to see it.
Falling for scams
Scams and hoax messages could come from your contacts or random numbers. Be suspicious of messages that sound too good to be true or threaten something bad will happen if you don’t forward the message. Some scams will ask you to share your personal info or tap on a link – don’t do it!
Clicking on random links
It’s easy to hide something unsafe inside a shortened link. If something looks suspicious or sounds too good to be true, don’t tap on it or forward it, even if it was sent by someone you know.
Forwarding messages without checking
Messages that spread false information are so common and are meant to cause panic. Check whether it’s true before forwarding a message, so you don’t become a source of unreliable information.
Mis-reading the tone of the message
Instant messaging misses out on emotional context and visual cues that you’d get with in-person conversation. Even in person, sarcasm can be misinterpreted, let alone in a text message where no one can see your face or hear the tone of your voice.
Joining group chats with random people
When you’re in a group chat, everyone in that group would see your phone number.
Sharing your status updates with your whole contact list
Everyone on your contact list (including your boss!) can see your status updates, unless you change your privacy settings.
Not changing your WhatsApp number when you sell your line
The new owner of your SIM card can access your WhatsApp chat history and receive any new messages sent to this number. To change the phone number associated with your WhatsApp account, go to WhatsApp settings > Account > Change Number. Doing this will migrate your old account data to your new number.
Using a public computer for WhatsApp Web
If you forget to log out of WhatsApp Web, the next person who uses the computer will have full access to your account. When signing into the web version of WhatsApp, un-tick “Keep me signed in” and make sure to log out when you’re done.
Alternatively, you can also log out of WhatsApp Web through the app on your phone: