Is all the form data sent when using a Page Method?

Question

I was under the impression that Page Methods and Script Methods created tiny AJAX requests (compared to PostBacks), but I'm inspecting an XHR of a Page Method call in Chrome's Developer Tools' Network tab, and seeing the entire form's data in the headers.
Since Page Methods are static and don't have access to Form values directly, it would make sense to me that the entire form isn't being sent.
Perhaps I'm just misinterpreting the Chrome Developer Tools?

Answer 1

That looks like a regular ASP.NET postback routed through an UpdatePanel. Implemented and called correctly, static page methods will only send POST data that you specify, not the entire form.

Can you post some code showing the server-side method and how you're calling it on the client-side?