Abstract: A client computer executes a client agent that determines the time between when an input is transmitted from a client computer to a remote server and when updated graphics are received from the remote server in response. The client agent interacts with a server agent that executes on the remote server. The client agent transmits an emulated keystroke to the server agent. In response, the server agent modifies a graphics object and composites the modified graphics object with a currently rendered frame. The client computer receives the frame and identifies the modified graphics object, indicating that the emulated keystroke was received by the remote server. The client agent then computes the time difference between when the emulated keystroke was transmitted to the remote server and when the modified graphics object was detected and/or displayed at the client computer. This time difference indicates the responsiveness of the remote desktop implementation.