Overview

WhatsApp was founded in 2009 by Brian Acton and Jan Koum, both former Yahoo employees, and grew into the world’s most widely used messaging app before Facebook (now Meta) acquired it in 2014 for roughly $19 billion. It adopted the Signal Protocol in 2016 to provide end-to-end encryption by default for one-to-one and group chats, a genuine security strength that predates similar defaults on many competitors.

WhatsApp’s client and server code are both closed source, and the service depends entirely on Meta’s infrastructure. Accounts are tied to a phone number, which Meta can cross-reference with other identifying data it holds. While message content is end-to-end encrypted, WhatsApp still collects substantial metadata — who you talk to, when, and how often — and shares data with the broader Meta family of products under its privacy policy. A 2021 update to that policy, which expanded data sharing with Facebook for business accounts, triggered a well-documented wave of users migrating to Signal and other alternatives.

Key Features

End-to-end encryption — Signal Protocol encrypts one-to-one and group messages, voice, and video calls by default
Cross-platform — Native apps for Android, iOS, Windows, macOS, and a linked web/desktop client
Voice and video calls — Including group calls with up to 32 participants
Status updates — Ephemeral photo/video/text updates similar to Stories
Business API — Widely used by companies for customer support and commerce, which drives much of Meta’s monetization of the platform
Large user base — Billions of active users globally, making it a de facto default in many countries

Use Cases

Personal messaging — The default choice in much of Europe, Latin America, Africa, and Asia
Small business communication — Customer support and order updates via WhatsApp Business
International calling — Free voice/video calls over Wi-Fi or mobile data, bypassing carrier rates

Who It’s For

WhatsApp suits people who prioritize near-universal reach — it’s often the only messaging app family, friends, or local businesses will actually use. It is a weaker fit for anyone who wants control over their data, dislikes being tied to a phone number and a single company’s servers, or is uncomfortable with Meta’s broader data-sharing practices even where message content itself is encrypted.