NOTE – A new version of the Amazon Mechanical Turk Requester UI Guide is available at This is official Amazon Web Services (AWS) documentation for Amazon Mechanical Turk. Amazon Mechanical Turk is a web service that provides an on-demand, scalable, human workforce to complete jobs that humans can do better than computers, such as recognizing objects in photographs. This guide provides a conceptual overview of Amazon Mechanical Turk and describes how to access Amazon Mechanical Turk functionality using a graphical user interface.