AFNetworking - do not cache response

Make long story short, just define your AFNetworking manager:

AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager];
[manager.requestSerializer setCachePolicy:NSURLRequestReloadIgnoringLocalCacheData];

Enjoy!

What you are experiencing is the effect of the URL cache (see NSURLCache).

The caching behavior of the request can be defined by setting a "Cache Policy" for the NSMutableURLRequest object, e.g.:

NSMutableURLRequest* request = ...;
[request setCachePolicy: myCachePolicy];

The default caching behavior (NSURLRequestUseProtocolCachePolicy) is appropriate for the current protocol, which is HTTP. And for the HTTP protocol, a GET requests will be cached by default!

And, AFNetworking does not change the default behavior of the request!

Now, you could set another cache policy, for example:

NSURLRequestReloadIgnoringLocalCacheData

Specifies that the data for the URL load should be loaded from the originating source. No existing cache data should be used to satisfy a URL load request.

This is likely the desired behavior you want to achieve:

[request setCachePolicy: NSURLRequestReloadIgnoringLocalCacheData];

The problem here is, that the super "convenient" API does not provide a way to configure the URL cache behavior of the request. You cannot access the used request at all.

Thus, I would suggest to use a lower level API where you have control about the created NSMutableURLRequest object, and set the cache policy accordingly.