WhatsApp vs. Signal: Which is more secure?

WhatsApp and Signal both offer end-to-end encryption. This technology works by scrambling the messages so that only the sender and receiver are able to put them back together. End-to-end encryption makes messaging more secure by making it impossible for any third party, including the app maker itself, to see the message contents.

However, we often hear that Signal is more private and secure than WhatsApp. Even we frequently recommend Signal as the most private messaging app out there. What exactly is behind this assertion? Between Signal and WhatsApp, which one is better? Read on for a detailed comparison.

Is Signal safer than WhatsApp?

WhatsApp and Signal both use the same encryption protocol developed by Open Whisper Systems. This protocol is open-source and peer-reviewed, making it trustworthy. While they use the same encryption, Signal has a number of security advantages over WhatsApp:

Metadata protection

When you send out a message or a photo, you are also sending out metadata. Metadata includes information about who the message is sent to, when the message was delivered, and more. While the content of messages is protected by end-to-end encryption, this metadata—information about the message—is not. If encryption is a lockbox, metadata is the postage label taped on top of it. Even without opening the box, you can already learn a lot by reading the label.

WhatsApp does not protect metadata. This means third parties may see information about the messages. In contrast, Signal developed a technology for protecting metadata called Sealed Sender. This technology hides information about the sender and the recipient, so even the postage label is unreadable.

Read more: What is metadata and what does it mean?

Data sharing

In addition to the messages and the metadata, messaging services can also collect information stored on your phone. This information includes your phone number, contacts, avatar, location, media, and device details. There is a major difference between how WhatsApp and Signal treat this information.

WhatsApp stores encrypted media and forwarded messages on its own servers. It also collects information on your usage habits such as how often you use the app and how much time you spend chatting with each contact. According to its privacy policy, third-party service providers can access this information. Signal, on the other hand, only requires a phone number. They will not attempt to link the phone number to an identity.

Company ownership

Another important factor to consider is which company owns the messaging service. Meta (formerly Facebook) owns WhatsApp. If WhatsApp’s privacy policy is any indication, they will integrate the app with other services owned by Meta. This involves sharing of information in order to help them customize and market their services.

On the other hand, Signal is owned by the Signal Technology Foundation. It is a registered non-profit organization that is run on user donations. One of the founders, Moxie Marlinspike, was Twitter’s head of cybersecurity. He developed Signal’s end-to-end encryption protocol, which was later adopted into popular messaging apps such as WhatsApp, Skype, and Facebook Messenger.

Read more: WhatsApp’s new privacy policy explained (2021)

Which messaging app is most secure?

Between WhatsApp and Signal, Signal wins hands-down as the more secure messaging service. While both use end-to-end message encryption, Signal provides more metadata privacy and doesn’t share your data with third parties. Since Signal is privately owned and non-profit, it will likely remain the more secure option in the near future.

That said, we aren’t necessarily recommending that you stop using WhatsApp. Admittedly, its end-to-end encryption is still a highly respected standard of privacy protection.