Here’s how to hide online or appear offline (even if you’re not) on WhatsApp.
On your WhatsApp dashboard, tap the three vertical dots in the upper right corner.
Tap on Settings. For iOS users, just tap on Settings from the menu on the bottom.
Click Account and then go to the Privacy option.
Simply tap the Last Seen option.
And choose Nobody if you want to hide your online status on WhatsApp messenger.