How to peek at messages in the queue
Right click no longer works in the new SQS console.
To view queue messages in the SQS console you now need to click into a queue > Send and receive messages > Poll for messages
Update 11/11/2020
Right-clicking no longer works on new SQS console.
See @marmor's answer
Original Answer (old dashboard)
If you have access to Amazon's AWS Console, on the queue list page, you can right-click on a queue.
Then select View/Delete Messages from the pop-up menu.
This will pop-up a window where you can start polling for messages in the queue.
Refer to images below:
There is no longer a true peek function available in SQS but you can probably accomplish what you want by simply using get_messages and setting the visibility_timeout quite low. As long as you don't delete the messages you have read, they will reappear on the queue after the visibility_timeout has expired and will be available for reading. The only tricky part is trying to figure out how long the timeout should be. If you have lots and lots of messages in the queue, you will have to make multiple calls to get_messages to retrieve them all and you probably don't want previously read messages reappearing while you are still peeking at the messages.