I’ve been testing messaging apps for years, trying to balance convenience, features and — crucially — privacy. If you’re like me, you want an app that lets you message friends on both iPhone and Android without handing over your metadata to advertising companies or centralized services that mine your contacts. Below I walk through four privacy-first messaging apps that actually work across platforms, explain how they protect your data, what trade-offs to expect, and which one I reach for depending on the situation.

What “privacy-first” actually means

Before we dive into apps, a quick note on terms because vendors and journalists sometimes blur them. When I say privacy-first, I mean an app that does at least these things:

  • End-to-end encryption (E2EE) by default for one-to-one and group chats.
  • Minimal metadata collection — the service does not build ad profiles or sell user data.
  • Transparent, preferably open-source code and independent audits when available.
  • Options to reduce linkability: no mandatory phone number, minimal contact discovery, or anonymous identifiers where practical.

    • No app is perfect, and trade-offs are inevitable: convenience often involves some metadata-sharing (like phone number discovery), and decentralized systems can add setup complexity. Here are four apps I use and recommend because they strike workable balances for different use cases.

    Signal — the default for balanced privacy and usability

    I reach for Signal when I want a no-fuss, highly secure chat that most privacy-conscious people already trust. It’s open-source, audited, and uses the Signal Protocol — one of the strongest E2EE protocols available.

  • Platform coverage: iOS, Android, macOS, Windows, Linux (desktop requires linking to phone).
  • Strengths: E2EE by default for everything; strong forward secrecy; disappearing messages; good voice and video calling; widely adopted among privacy-aware users.
  • Trade-offs: Requires a phone number for account creation, and the Signal server has access to a limited set of metadata (e.g., when you registered and the last connection time), though they store far less than most services.

    • Signal’s security model is straightforward: cryptographic keys are stored locally, and messages cannot be read by the company. If you’re okay using your phone number as an identifier (or using a secondary number/VoIP in some cases), Signal is the most practical privacy-first option for daily use.

    Element (Matrix) — for power users and federated control

    Element is a client for the Matrix protocol. Matrix is federated: anyone can run a server, and servers can communicate with one another. That makes Matrix/Element particularly appealing if you want more control over who hosts your data.

  • Platform coverage: iOS, Android, Windows, macOS, Linux, and web.
  • Strengths: Federation and self-hosting options, robust group chat features, bridges to other platforms (IRC, Slack, Telegram), open standard and open-source clients/servers.
  • Trade-offs: Encryption is provided via Matrix’s Megolm/Olm schemes — strong but more complicated in larger groups; not every Matrix server will implement metadata protections equally; user experience can be more technical than Signal.

    • I like Element when I want to host my own server (so I control logs), or when a community needs bridges to other services. If your contacts are technically inclined and you want to avoid central servers, Element/Matrix is powerful — just be mindful that federation means your privacy depends partly on the server you pick.

    Threema — paid, private, and minimal-identifiers

    Threema takes a pragmatic approach: it’s a paid app with a strong privacy posture. Because it doesn’t rely on ad revenue, Threema’s business model avoids the incentive to collect and monetize user data.

  • Platform coverage: iOS, Android, web (via QR code pairing).
  • Strengths: No phone number or email required — accounts can be created with a random Threema ID; E2EE for messages, voice calls, and files; small, privacy-focused company based in Switzerland with strong local privacy laws.
  • Trade-offs: It’s paid (one-time fee on app stores), which is actually a pro from a privacy perspective, but the cost might deter casual users. Smaller ecosystem than Signal, so fewer of your contacts may already be on it.

    • Use Threema when you want maximum anonymity without sacrificing polished apps. Because you can sign up without a phone number or email, it’s my pick for privacy-sensitive conversations with contacts who are willing to pay a small fee for the app.

    Session — anonymous and metadata-resistant

    Session is built for people who want messaging with minimal metadata and without using a phone number. It uses a decentralized onion-routing network and randomized IDs instead of phone numbers, and it doesn’t require central servers that store your contact list or connection times.

  • Platform coverage: iOS, Android, desktop clients.
  • Strengths: No phone number, no contact discovery via address book by default, metadata-resistant design, open-source.
  • Trade-offs: Some features are intentionally limited to protect privacy (for example, real-time status and contact discovery are constrained), and the UX can feel slower or less polished than centralized services because of the onion routing.

    • Session is my go-to for ultra-private chats where even the act of linking a phone number is unacceptable. It’s excellent for whistleblowing-style needs or when you want to minimize any traceable link between you and your messages.

    How they compare at a glance

    App Phone number required Federation / self-hosting Open source Best for
    Signal Yes No Yes Everyday secure messaging with great UX
    Element (Matrix) Optional Yes (self-host possible) Yes Communities, self-hosting, bridging services
    Threema No No (but privacy-focused servers) Partially (clients are open) Anonymous accounts and paid privacy
    Session No Yes (decentralized onion routing) Yes Maximum metadata-resistance

    Practical tips for switching and staying private

    Here are a few practical things I do when moving to a privacy-first messenger:

  • Don’t disable phone security: lock screens and biometrics still protect your local message store.
  • Check backup options: Signal encrypts local backups but prohibits cloud backups by default; Element provides export tools if you self-host; Threema offers encrypted backups. Consider whether you want cloud backups — they can leak metadata or message contents if not encrypted.
  • Be careful with contact discovery: automatic address-book upload is convenient but sends contact hashes to servers. Signal and others offer private contact discovery methods, but if extreme privacy matters, don’t enable contact sync — instead share IDs or invite links.
  • Keep software updated: security updates matter. These apps release critical fixes regularly, so enable automatic updates where possible.

    • Which one do I use and when?

    I use Signal for most of my day-to-day conversations — it’s polished, secure, and my circle of contacts is there. For work communities and projects where self-hosting or bridging matters, Element is my choice. If I need absolute anonymity or to set up a throwaway identity for sensitive exchanges, I’ll create a Threema ID or use Session depending on the situation.

    If you want to keep things simple and ensure the broadest compatibility with both iPhone and Android without sacrificing strong encryption, start with Signal. If you’re comfortable paying a small fee for extra anonymity, Threema is excellent. For federated control or bridging requirements, pick Element; and if metadata-resistance and anonymous IDs are critical, try Session.

    If you want, tell me what you need most — group chats, voice/video calls, anonymous sign-up, or bridging to other platforms — and I’ll recommend which of these four fits your workflow best and walk you through setup steps tailored to your priorities.