Sleeper is a utility program designed for Windows that tests PC systems' ability to transition into various sleep states and hibernation modes. This tool is particularly useful for users looking to ensure their systems can effectively manage power-saving states. With Sleeper, users can initiate sleep states (S1, S2, S3) and hibernation (S4), verify system responsiveness, and automate testing processes via command line functionalities.

The program supports a range of features including the ability to wake the computer after a specified duration, force transitions into requested sleep states, and cycle through all available states. Additionally, Sleeper can be integrated with PassMark BurnInTest scripts, allowing for comprehensive testing between runs. The interface displays all supported sleep states, making it a valuable tool for both casual users and IT professionals.