One embodiment of the present invention sets forth a technique for testing a client for audio/video/subtitle playback capabilities. A computing device is configured to receive a virtual machine data file that includes an operating system, a web server, a content playback application, and a test program. The virtual machine data file is executed to cause the operating system and web server to initialize. The web server detects a communications connection to the client, transmits the content playback application to the client for execution, and transmits one or more tests included in the test program to test the audio/video playback capabilities of the client. The computing device is further configured to receive, from the client via the web server, test results associated with the one or more tests, and to store the test results in a memory.