Digital tools, technologies, and infrastructures have increasingly shaped how knowledge is understood, created, managed, maintained, and shared. In sectors such as cultural heritage, for example, curators and scholars now widely apply computer science approaches to their collections for tasks such as enriching content and providing users with visual access. Although there has been an increasing interest in critical digital visual design and cultural heritage, what still seems to be largely missing is a problematised and critical approach to the application of these techniques. Drawing on critical posthumanities, in this article I propose a new critical framework, the post-authentic framework to digital objects and cultural heritage. The framework advocates transparency and openness as well as the active and reflexive participation of the scholar/curator in the process of knowledge production. To exemplify how the post-authentic framework may be applied to digital research, I explore two use cases: critical visualisation design and critical digital heritage research. For the first use case, I examine the design choices for developing the tool DeXTER, an interactive visualisation app that allows users to explore enriched cultural heritage material interactively. I specifically emphasise the challenges facing product design, with a focus on visualising the ambiguities and uncertainties of Network Analysis and Sentiment Analysis. For the second use case, I explore the potential of DeXTER for testing hypotheses on large textual collections, for example by accessing the layers of meaning attached to referential entities. The use case is the Italian American labour movement from 1898 to 1936. The article concludes with key concepts and methods for applying the post-authentic framework to digital heritage practices and knowledge creation more widely.