1. A method in a server for improving the loading of web resources, the method comprising: receiving a request from a client network application for a Hypertext Markup Language (HTML) document, wherein the request identifies a domain that hosts the HTML document; retrieving the requested document; automatically modifying a plurality of objects referenced in the HTML document that have an external source such that loading of the plurality of objects by the client network application will be deferred; inserting a client-side script loader or a reference to the client-side script loader into the HTML document, wherein the client-side script loader is configured to, when executed by the client network application, attempt to load the plurality of objects; and transmitting the modified HTML document to the client network application.