Both Signal and WhatsApp use end-to-end encryption. So why do privacy experts universally recommend Signal and treat WhatsApp with skepticism? The difference is about more than just the encryption.
What End-to-End Encryption Means
End-to-end encryption means only the sender and recipient can read message contents. Not the company, not the government (without device access), not your ISP. Both Signal and WhatsApp use this for message content.
But message content is only part of what a messaging app knows about you.
What WhatsApp Collects
WhatsApp is owned by Meta (Facebook). While WhatsApp can't read your messages, it collects significant metadata:
- Who you message and how often
- When you're online and for how long
- Your phone number, contacts, and their phone numbers
- Your device identifiers, IP address, and location
- How you use the app
This metadata is shared with Facebook/Meta. Knowing who you talk to, when, and how often is often more valuable to advertisers and governments than knowing what you said.
In 2021, WhatsApp updated its privacy policy to require data sharing with Facebook for business messaging features, causing a mass exodus of users to Signal and Telegram.
What Signal Collects
Signal is operated by a nonprofit foundation. It collects only what's minimally necessary to function: your phone number (required to register) and the last time you connected to Signal's servers. That's it.
Signal's code is fully open source. It has been independently audited multiple times. It has never been found to collect data beyond what it claims.
When the FBI subpoenaed Signal for data on a user in 2016, Signal's response was: the only data it had was the account registration date and the date of last connection. No messages, no contacts, no metadata.
Telegram Is Not the Same as Signal
Many people switched from WhatsApp to Telegram, not Signal, in 2021. This was a significant privacy downgrade. Telegram's default chats are NOT end-to-end encrypted — they're stored on Telegram's servers and Telegram can read them. End-to-end encryption is only available in Telegram's "Secret Chats" feature, which requires you to manually start a secret chat rather than a regular one.
Telegram is a useful tool, but it's not a private messaging app in the same sense as Signal.
The Bottom Line
For private communication, Signal is the correct choice. The switch takes about five minutes. The only trade-off is convincing the people you communicate with to use it too — the protection only applies to Signal-to-Signal conversations.
For group chats and people who won't switch, WhatsApp with end-to-end encryption is significantly better than unencrypted SMS. Just understand that Meta is collecting your metadata.