This chapter discusses the concept of usability and how it can be applied to translation. First, it introduces some usability definitions. Second, describes the development of usability discussions from an engineering approach to user-centered design and to the latest wave of user experience. Third, address the idea of cultural usability and the ways in which it links to the practice of translation. Usability is one key area of the Human-Computer Interaction (HCI) discipline. Initially, it was known as Usability Engineering, but is now also called Usability Research, expanding from engineering into other user-centered research designs as well as to the development of suitable usability methods. Translation studies scholars have recently expressed growing interest in the affective aspects of translating and translations, but direct links to user experience design are still few. The chapter concludes with a discussion of user experience. It covers all the interaction that the end user has with a company, its services and its products.