The use of private social media has rocketed in the last decade. However, we still know little about the extent to which citizens see them as channels of political communication. Some studies have approached this matter, but predominantly focusing on the instrumentalization of these platforms’ public groups to spread misinformation in the Global South. A few others have examined the implications of discussing politics through these platforms but have failed to conceptualise the multifaceted nature of that discussion. Thus, we lack a comprehensive understanding of whether and how exactly citizens utilise private social media for politics, including whereabouts information is accessed and political talk takes place, with whom, and why. This paper aims to fill this gap by focusing on WhatsApp. Harnessing the uniqueness of Spain, where 90% of the population uses this platform, we conduct a novel representative survey (n = 800) on individuals’ WhatsApp political practices and complement this information with a comprehensive set of ten in-depth focus groups involving more than 50 participants. Building on these data, we show the variety of political experiences available in the platform, establish a typology of WhatsApp political users and conversations (empirically documenting their relevance), and characterise the spaces where those conversations occur, as well as the role that emotions play in them. Ultimately, we aim to elucidate whether –and when– individuals fragment themselves into echo chambers when making a political use of WhatsApp. Though evidence on public social media tend to reject the fragmentation hypothesis, the privacy and strong-tie connections of WhatsApp groups may provide a singular opportunity for homophilic expression and tribal in-grouping.