There are a couple of ways for WhatsApp users to figure out whether someone has blocked them on the Whatsapp. 

Why Whatsapp Don't Inform You When Someone Blocked You?

Because it is focused for protecting user's privacy, WhatsApp does not give information to users whether they have been blocked by someone. Although it does not expressly state whether or not someone has blocked you, there are several signs to figure out that you have been blocked. If you've been blocked, here's how to find out.

Signs That Indicates, You Have Been Blocked By Someone:

WhatsApp, which is owned by Facebook, has set up several indications to see whether you've been blocked on the messaging service. Keep in mind, however, that these signs do not ensure that you have been blocked by a contact.

Check The Last Seen

Checking their last seen or online status in the chat window is one of the simplest methods to do so. But one thing to note that, if you would not be able to see Last Seen of someone this setting may have been deactivated by the user, so you won't see Last Seen.

Check The Profile Picture

You won't be able to view someone's profile picture if they have blocked you on WhatsApp. If you can view that person's profile picture and you've been blocked in the meanwhile, you might not be able to see their new profile picture.

Related Articles: How WhatsApp Secures Our Chats? What is End-to-end Encryption? Role Of Security Code

Send A Message

If you send a message to someone who has blocked you, you will only see a single check mark once the message has been sent. There will be no double check marks or blue check marks (read receipts).

This occurs because single check mark appears on whatsapp when a message sent from your side for another user. And double check mark appears when message received by another user. When a person block another person, then message from the side of blocked person will be sent to another user but that message will not recieve to other user. So single check mark appears but neither double check mark nor blue check mark will appear.

Make The Call Through Whatsapp

It's possible that your attempts to call contact will be unsuccessful. When you make a call, you'll only see one calling message. However, this can happen even if the call recipient does not have access to the internet.

Create A Group

If you try to create a group with a contact you believe has blocked you, you will be the only one in that group once you've completed the procedure.