WhatsApp is the default messaging app for most of Europe. It is also owned by Meta Platforms, Inc. (US-incorporated), which places the parent group under US CLOUD Act jurisdiction. WhatsApp encrypts message content end-to-end, so the practical concern is not that messages are readable; it is the ownership structure and the metadata layer: contact graphs, who-messages-whom, timing, and the contact-discovery-by-phone-number mechanism that ties your identity to your SIM. For a privacy-conscious individual, a journalist or legal practitioner with a threat model, or a European organisation writing a data-sovereignty assessment, that profile is what prompts a look at the five alternatives below, weighed on who legally owns the company, where the servers sit, whether metadata is protected as well as content, and whether the app can run inside your own perimeter.
All five options below are end-to-end encrypted by default, so what actually separates them is where your conversations and metadata end up, and under whose jurisdiction. Threema is the easiest consumer-ready switch (Switzerland, Pfäffikon, EU-owned, all-Swiss hosting, CLOUD Act exposure: None, ISO 27001, no phone number required), Olvid is the government-grade French option and the only one here that end-to-end encrypts metadata as well as content (France, Paris, EU-owned, ANSSI CSPN-certified, mandated for French government ministers), and Element/Matrix is the open, federated, self-hostable choice for organisations (United Kingdom, open-source Matrix protocol, used across European public sectors).