This study examines the varying interpretations of data portability across different legislative frameworks. While each legislation labels the concept as “portability,” the underlying perception of what constitutes portability significantly differs. This divergence in conceptualization, rather than mere definitional variation, not only leads to confusion but also affects the rights and obligations of relevant stakeholders, as well as the design of portability technologies. The focus on the distinct perceptions of the concept enables the reconstruction of a minimal definition of portability and differentiate between “types” in the portability spectrum. This chapter shows that the notion of data portability has undergone a substantial transformation: Initially centered on empowering users by enabling data export and transfer, it has progressively shifted focus to benefit the data market, by making data accessible to various entities in an easily modifiable, machine-readable format. The metamorphosis of portability is complete in the Data Act: from larva to moth—the meta-moth-phosis.