Secure Messaging: WhatsApp, Signal & Telegram

Encrypted messaging apps changed how we communicate. WhatsApp, Telegram, and Signal are three of the most popular choices - but they differ a lot in features, privacy, and design philosophy. Below is a practical, user-focused comparison to help you pick the right app for your needs.

Quick overview of each app ​

WhatsApp​

Founded by Jan Koum and Brian Acton in 2009 and acquired by Facebook in 2014, WhatsApp is a mobile-first app available on Android, iOS, and desktop. It uses end-to-end encryption (E2E) based on the Signal protocol for messages, calls, photos, and videos. WhatsApp supports group chats (up to 256 members), voice & video calls, file sharing, live location, and cloud backups via Google Drive or iCloud (which are not E2E encrypted by default). WhatsApp Business exists for companies to interact with customers.

Telegram​

Launched by Pavel and Nikolai Durov in 2013, Telegram is a feature-rich, cross-platform messaging app with native clients for mobile and desktop. It supports massive groups (up to 200,000), channels, bots, polls, and extensive file sharing (up to 1.5 GB). Telegram offers “Secret Chats” that are E2E encrypted, but regular cloud chats use Telegram’s own server-side encryption, which is different from true E2E for group and cloud-synced chats.

Signal​

Signal is a privacy-first, non-profit app that rose in popularity because of its strong default privacy posture. Signal provides true E2E encryption for messages, voice and video calls, disappearing messages, and (with metadata protections) extra attention to minimizing what is stored about you. Signal keeps minimal user data - basically only the phone number - and the protocol has strong peer review and open-source code.

---

Security & privacy: what really matters ​

• End-to-end encryption (E2E):
  • Signal = All chats, calls, and attachments are E2E by default (including groups).
  • WhatsApp = E2E for messages and calls by default, using the Signal protocol.
  • Telegram = Only Secret Chats are E2E; normal chats are server-side encrypted for cloud sync.
• Metadata handling:
  • Signal collects minimal metadata (phone number only) and works to obscure other traces.
  • WhatsApp collects more metadata (contacts, usage, device info) and links to Facebook’s ecosystem.
  • Telegram claims limited sharing but stores cloud chat metadata on its servers.
• Backups:
  • WhatsApp backups to Google Drive/iCloud are not E2E unless you enable the optional E2E backup feature (check current app settings).
  • Telegram stores cloud messages on servers (accessible if keys are held server-side).
  • Signal does not back up to cloud by default; local backups are encrypted.
• Open source & auditability:
  • Signal and Telegram are (largely) open source and have public protocols (Signal’s protocol has strong academic review).
  • WhatsApp uses open Signal protocol but its app and server ecosystem are controlled by Meta.

Features at a glance - practical differences ​

• Group size: Telegram (200k) » Signal (~1,000) » WhatsApp (256).
• Bots & automation: Telegram > WhatsApp > Signal.
• File size limits: Telegram up to 1.5 GB; WhatsApp smaller (100 MB attachments typical); Signal smaller but secure.
• Cross-device sync: Telegram and Signal support multi-device; WhatsApp requires phone for initial web/desktop login.
• Advanced group tools: Telegram supports polls, channels, pinned messages, folders, usernames - many social features WhatsApp lacks.

What each app collects (high level) ​

• WhatsApp: device and user IDs, contact lists, usage & diagnostics, payment info (where applicable), and more.
• Telegram: basic contact info and user IDs; cloud data is hosted on Telegram servers.
• Signal: minimal - essentially only your phone number; no message content, and limited metadata retention.

Which app should you choose? ​

• Choose Signal if: privacy is your top priority and you want the strongest defaults for message and metadata protection. Best for individuals focused on secure conversations.
• Choose WhatsApp if: you want widespread adoption, reliable E2E for messages/calls, and easy contact integration - but accept that backups/metadata may be less private. Good when most of your contacts already use it.
• Choose Telegram if: you want advanced community features (large groups, channels, bots) and cloud sync across devices - but be mindful that standard chats are not E2E by default.

You can also use apps together: Signal for private chats, Telegram for large communities and file sharing, and WhatsApp for everyday contacts.

Final thoughts - pick what fits your threat model ​

No single app is ideal for every case. If your primary concern is maximum privacy, Signal is the best default choice. If you need large group features and social tools, Telegram is powerful. For mainstream, cross-platform convenience, WhatsApp is widely used - just be careful with cloud backups and what metadata you expose.