Burp Repeater is a tool to send HTTP requests and see their responses one by one. Consider it like a scratch pad. You can manually change parameters, request methods, and see the response. The power of Repeater comes with its integration with the rest of the suite. We can send a request from anywhere to Repeater to be worked on, and we can create a brand new request as well:

Repeater's user interface is quite bare, and it can seem a little confusing at first. As I mentioned before, the common way of using Repeater is to send a request to it. But otherwise, we need to set the Host and Port values we would like to send the request to. This can be done by clicking on the Edit host button in the top-right corner and adding the proper values. Have a look at the following screenshot:

Once the host and port are set, we can start making HTTP requests using a very basic interface, as shown in the following screenshot:

All the requests that get sent to the Repeater tool are sequentially numbered...