Signal is fundamentally designed from the ground up to prioritize privacy and security as its core mission, while WhatsApp, despite using some of the same encryption, is owned by Meta (Facebook), a company whose business model is based on collecting user data.
Here’s a detailed breakdown of why Signal is considered superior for privacy:
- The Business Model: The Most Critical Difference
This is the root of all other differences.
· Signal: A non-profit organization (Signal Foundation) funded by grants and donations. It has no investors to please and no need to generate profit. Its only product is a secure messaging app. Their incentive is to provide the best privacy possible to attract users who value that.
· WhatsApp: Owned by Meta, a for-profit publicly traded company. Meta’s primary revenue comes from targeted advertising. While WhatsApp currently doesn’t show ads in chats, its privacy policy explicitly allows it to share a significant amount of metadata with Meta for purposes like “improving infrastructure and delivery systems,” “showing relevant offers and ads across the Meta Company Products,” and “providing integrations” (e.g., connecting your WhatsApp account to your Instagram account).
- Data Collection: What They Know About You
This is the most practical consequence of the different business models.
· Signal: Collects virtually no data. The only information linked to your account is your phone number and the date you registered. Everything else is designed to be ephemeral and unknown to Signal.
· Message contents: Fully encrypted. Signal cannot read them.
· Metadata: Signal’s design minimizes metadata. It does not know who you are messaging, when you message them, your group memberships, your profile name, or your contacts. This data is not stored on their servers.
· WhatsApp: Collects extensive metadata. While your messages are encrypted, a vast amount of data about your activity is not.
· Message contents: Fully encrypted. WhatsApp cannot read them.
· Metadata: WhatsApp collects and shares with Meta: your phone number, your contacts’ phone numbers, your group names and participants, your status updates, the time you are online, your location (if shared), your device information, and your IP address. This metadata creates a detailed social graph of your life, who you talk to, and when.
- Technical Implementation and Openness
Trust is earned through verification, not through marketing.
· Signal: Fully Open Source. Both the client (the app you use) and the server code are publicly available for anyone to inspect, audit, and verify. This transparency means security experts around the world can constantly check for vulnerabilities and confirm there are no backdoors. The Signal Protocol is the gold standard for encryption and is actually licensed by WhatsApp, Skype, and Facebook Messenger.
· WhatsApp: Closed Source Server. While the WhatsApp client app is partially open source, its server code is completely proprietary and secret. This means no one outside of Meta can verify what happens to your data once it reaches their servers or how the encryption is truly implemented. You have to trust Meta’s word.
- Ownership and Identity
· Signal: Ties your identity to your phone number (a known weakness, but they are working on usernames to address this).
· WhatsApp: Ties your identity to your phone number and, by extension, your Meta/Facebook profile. This creates a much richer and more invasive data profile.
- Features Designed for Privacy
Signal includes features that WhatsApp lacks, which give you more control:
· Sealed Sender: This feature hides even the sender’s information from the server, further protecting metadata.
· Relay Calls: Signal can route your voice/video calls through its servers to hide your IP address from the person you’re calling.
· Screen Security: Prevents apps from taking screenshots of your chats on Android (e.g., in the recent apps view).
· No Cloud Backups (by default): Your messages stay on your device. While you can enable encrypted backups, they are opt-in and protected with a password that only you know. WhatsApp encourages automatic, unencrypted backups to Google Drive/iCloud, which are outside its encryption umbrella and can be accessed by law enforcement or hackers.
Conclusion
Think of it like this:
· WhatsApp is a secure tunnel for your message content, but the company owns and monitors the highway the tunnel is built on (who you talk to, when, and where). They use this highway information for their business.
· Signal not only provides the secure tunnel but also built a private highway system where no one, not even Signal itself, can monitor the traffic.
If your goal is to prevent a random hacker from reading your messages, both apps are excellent. However, if your goal is to protect your privacy from the app maker itself, its parent company, and the data economy they operate in, Signal is the unequivocally superior choice.