<p>This paper introduces a Heideggerian existential typology for understanding digital human twins—advanced, real-time digital replicas of individuals—as a philosophical response to pervasive datafication and personalized AI systems. Drawing from Heidegger’s concepts of <i>Dasein</i> (being-there), authenticity (<i>Eigentlichkeit</i>), and technology as enframing (<i>Gestell</i>), alongside Boddington’s embodied technology framework, we propose a structured 2× 2 matrix categorizing digital twin experiences along dimensions of authentic vs. inauthentic self-engagement and existential integration (Digital Dasein) vs. objectifying datafication (Existential Datafication). Four distinct existential modalities emerge—Digital Dasein, Alienated Authenticity, Transparent Inauthenticity, and Existential Datafication—each explored through illustrative scenarios. This typology highlights crucial ethical and societal tensions concerning identity, autonomy, and agency in increasingly data-driven contexts, advocating for human-centered design principles to safeguard authenticity and human flourishing.</p>