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ioscharles-proxy

Charles, empty request body with non-empty response body

I used Charles to record a session and when I check one of the sessions, I found that there is no request body but I can see a response body, I am confused about this as how am I seeing a response without sending a request?

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Also, I noticed that I can choose to see the request and response body on my phone's Charles, but on my desktop Charles, I can only see the tab called Content, I tried clicking on the request and response in the under the View tab, nothing happened as well. Does anyone know why? enter image description here

Thanks!

Solution

  • I am confused about this as how am I seeing a response without sending a request?

    A request consists of a few things:

    • Always: an HTTP method (GET, POST, or similar)
    • Always: a path (/document/123)
    • Optional: any number of HTTP headers (my-header: abc)
    • Optional: a request body

    A response consists of:

    • Always: an HTTP status (404)
    • Always (in HTTP/1): an HTTP status message (Not Found)
    • Optional: any number of HTTP headers (my-header: abc)
    • Optional: a response body

    In your case, you are sending a request, it's just that your request only contains a method, URL and headers, but no body. That's totally normal and this is very common for most HTTP requests.

    The request and response body are totally independent: it's fine for neither to have a body, or for just one (either one) to have a body, or for both to have a body.

    As an example, a GET request to https://google.com/search from a browser will include a method (GET) and a path (/search) and a selection of headers from the browser (such as a user-agent), but won't include any body, and the response will have a status (200) and message (OK), headers about the response data (e.g. content-length: ...) and the body will be the HTML for the google search page.