This method is the same for both Android and iPhone models. First, open Snapchat on your phone and log in to your account. Tap the chat icon at the bottom to switch to the chat screen.
Now, you will need to use a little trick to look at the message you received without the person knowing. To do this, simply place your finger on the person’s profile and slowly drag your finger from left to right without fully opening the screen. This way, you will have partially opened the chat screen.
You must do this carefully so as not to open the chat completely. You can see the message without actually opening it. The important point here is not to swipe the screen all the way across.
If you do it correctly, Snapchat will not mark the message as read. That’s it. With a little swipe and peek, you can check messages without being seen.