How does HTTP 302 work?

Question

How does HTTP 302 work? I would like to know the internals

Answer 1

You mean how do browsers handle it? The server sends a 302 code along with a Location header, and the browser requests the new URI specified by the Location header instead.

Unlike 301 (Moved Permanently), the browser continues to use the original URI to do requests, in case the 302 code goes away

Answer 2

The internals of what? 302 is a return code the server gives the client, what the client does is upto it. The RFCs give guidance on what the client should do, but in the real world 301, 302, 303 and 307 are all handled the same way by the mainstream browsers.

Answer 3

The server returns an HTTP response with the code 302, indicating a temporary redirection, and includes a Location: header indicating the new URI, e.g.

HTTP/1.1 302 Found
Location: http://some-other-url

And potentially other headers at the server's discretion.

The browser normally takes this as a directive to automatically make a new, separate request for the other URI specified by the location header. The client (browser) isn't forced to do this (it could, in theory, just display a message to the user, or do whatever else it wants), but that's how HTTP clients usually behave.

Note that since the 302 is a temporary redirection, a well-behaved client will continue to use the old URL in the future, rather than going directly to the new one (301 is a permanent redirection).