How to read WhatsApp messages without the sender’s knowledge of the message, there is a way. A simple way to do this is to turn off the blue ticks indicating that the message has been read. But, there is a problem here. If you turn it off in Settings, you will never know if someone else has read your message. But if you do not want to know this, go straight to WhatsApp.
You can turn it off in the Read option by selecting the Account> Privacy> option and swiping to the left. But there is another way to be better than this. Put the phone in airplane mode before opening the WhatsApp, and then read the messages. Then the sender will not know that you have read the message.
Another strategy you can follow to make your presence less visible on WhatsApp is to turn off the last thing you see. Navigate to Settings> Click on Account> Select Privacy. There, select the Last Scene option. Here you will see three options. At the end of it, there will be an option called Nobody. Select it.
Whenever you see a message you can mark a WhatsApp message as ‘Unread’ and remember not to read it and then read and reply. To mark a message as unread, tap and hold the sender’s message without opening it, and then press the three dots on the top right. Then select the Unread option from here. The sender knows that the message has been read, but will remind you that it was not read with a blue or green dot.