In the history of external information systems, the World Wide Web presents a significant change in terms of the accessibility and amount of available information. Constant access to various kinds of online information has consequences for the way we think, act and remember. Philosophers and cognitive scientists have recently started to examine the interactions between the human mind and the Web, mainly focussing on the way online information influences our biological memory systems. In this article, we use concepts from the extended cognition and distributed cognition frameworks and from transactive memory theory to analyse the cognitive relations between humans and the Web. We first argue that while neither of these approaches neatly capture the nature of human-Web interactions, both offer useful concepts to describe aspects of such interactions. We then conceptualize relations between the Web and its users in terms of cognitive integration, arguing that most current Web applications are not deeply integrated and are better seen as a scaffold for memory and cognition. Some highly personalised applications accessed on wearable computing devices, however, may already have the capacity for deep integration. Finally, we draw out some of the epistemic implications of our cognitive analysis.