Is it possible to hack someones WhatsApp and get complete access to do everything that can be done with WhatsApp? The simple answer is YES. This post will take you through the steps to hack a WhatsApp account.

Note that you have to get access to the person's phone physically. This shouldn't be difficult since you definitely know the person you want to hack and close to him or her.

On your smartphone, you need one of the following browsers installed
  • Chrome
  • Firefox
  • Opera
Open your browser and goto web.whatsapp.com . This should take you to the mobile version of WhatsApp website.
Tap the 3 dots at the upper right corner of your browser to show options. From the options, check ' Request desktop site '
The page will reload and you'll have the page shown in the image below.
Note: Do not close this page because you will be scanning the QR code with the victim's phone
This is where the phone of the person you want to hack comes in. Open WhatsApp on the phone you want to hack.
Tap the 3 dots at the upper right corner to show options.
From the options, tap ' WhatsApp Web '
This will open up a screen where you'll have to scan the QR code on your phone. See the image below
Make sure you position the victims phone over yours in such a way that the QR code is visible in the box on the screen as shown in the image above.
This will scan the code and the connection will be established.

When you are connected, distance is not a barrier. Anytime the victim's phone to be connected to the internet, you have full access and control over his or her WhatsApp. 
You can;
Read new and past messages
Send messages
Download videos and pictures
Make calls
Change profile picture
etc.
All of these will be done within your browser where you have a beautiful normal WhatsApp interface.

Pretty cool ha :)
Please use this trick wisely as it may lead to undesirable consequencies because the victim may not take it lightly. My best friend nearly slap the hell out of me because I hacked his WhatsApp.  :)
All the best in your spying endeavor