How to block someone on WhatsApp without opening their message
This tutorial will show you step by step how to block someone on WhatsApp without opening and reading their message. The steps also work for unknown numbers.
Methods:
The steps on this page work for all Android phones, such as Samsung, Lenovo, Motorola, OnePlus, ASUS, Nokia, Google, Sony, LG, and other Android smartphones.
How to block an unknown number on WhatsApp without opening the message
Below, you'll find steps for blocking a phone number on WhatsApp that's not on your contact list without opening the message.
The trick is to add this number as a contact, block the contact on WhatsApp, and then delete the contact from your phone.
1. Open WhatsApp.
2. Long-press (press and hold) on the message until options appear at the top of the screen.
3. Tap on the ⁝ menu icon located in the top right corner.

4. Tap on Add to contacts.

5. Tap on Create new contact.

6. Enter any name you want.
7. Tap on Save.

8. Go back to WhatsApp.
9. Tap on the ⁝ menu icon located in the top right corner.

10. Tap on Settings.

11. Tap on Privacy.

12. Tap on Blocked contacts.

13. Tap on the “+ contact” icon located in the top right corner.

14. Tap on the contact you've just created.
The number is now blocked on WhatsApp.
You will no longer receive calls or messages from this number.
You can now also delete this contact from your phone if you want. If you delete this contact from your phone, the number will still be in your WhatsApp “Blocked contacts” list.
To unblock someone, you open settings > Account > Privacy > Blocked contacts > tap on their name or phone number > Unblock [name] or Unblock [phone number].
How to block a contact on WhatsApp without opening the message
1. Open WhatsApp.
2. Tap on the ⁝ menu icon located in the top right corner.

3. Tap on Settings.

4. Tap on Privacy.

5. Tap on Blocked contacts.

6. Tap on the “+ contact” located icon in the top right corner.

7. Tap on the contact you want to block.
The contact is now blocked on WhatsApp.
This contact will no longer be able to call you or send you messages.
To unblock someone, you open settings > Account > Privacy > Blocked contacts > tap on their name > Unblock [name].
Related:
WhatsApp privacy settings: last seen, online, read receipts
How to prevent your WhatsApp account from being hacked
How to silence calls from unknown numbers on WhatsApp
How to block a phone number on a Samsung phone (step by step)
How to disable “WhatsApp Web is currently active” notification
How to change a WhatsApp chat background on an Android phone
How to hide your last seen and online status on WhatsApp Web