This method does not completely turn off cellular data but lowers it instead. You can still use WhatsApp without Wi-Fi, but the quality of pictures in your messages and phone calls will be decreased.
To disable this mode, repeat these steps and tap the switch off. It’ll be grey or white to indicate that the feature is off.
This method will still let WhatsApp use cellular data, but your background downloads (like the pictures sent in your chat messages) will not download until your iPhone is connected to a Wi-Fi network.
You can always return to these settings to re-enable them. When you get a picture in a chat and you’re not connected to Wi-Fi, your phone will no longer automatically download it. However, you will see a placeholder image that you can tap to force the image to download over your mobile data connection.
