Yes, You make a empty container like a panel control "<div id="container"></div>" on your webform or user control, assign an ID to the container, then the server renders the page and sends the HTML to the users browser. You then write Javascript or JQuery to wait for the DOM to be ready. Now make the call to the web service, parse the JSON response, and use JQuery to populate the container with JQuery written HTML tags, and your JSON data. You just need a container to populate rendered by the server, and on the client side, fill the container, but the DOM has to be ready. While the container is waiting to be populated, and progress indicator can be displayed until the web service is done.