A technology is described for generating window images of a program window in a service provider environment and providing the window images to a client device for display on the client device when a preview event is detected on the client device. An example method may include detecting a modification to a program window associated with a program hosted on a computing resource located in a service provider environment, obtaining a window image of the program window capturing a graphical state of the program window, and sending the window image to the client device to allow the client device to display the window image on the client device in response to a preview event on the client device that is associated with the program window.