Is Signal Safe? How Secure Is This Privacy-Friendly Chat App?

Person with a smartphone, a lock and a shield with a question mark next to a big Signal logo
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Is Signal Safe? A Short Summary

Signal is advertised as a secure chat app, but how safe is it? All the messages you send on Signal are encrypted, and your profile is, too. The app doesn’t log any user data.

You don’t need to provide any personal information to create an account — just your phone number. Signal also doesn’t show any ads or track users. Its software is open source, and it is run by the non-profit Signal Foundation.

Signal is more secure than WhatsApp, and it comes with several features that allow you to take charge of your privacy. You can:

  • Enable expiring messages
  • Turn on app lock
  • Turn on watch prevention
  • Turn on call forwarding
  • Turn off preview images
  • Use a VPN

When it comes to VPNs, we recommend NordVPN for its rock-solid security and fast servers.

Read the article below to learn all about Signal’s privacy and security.

Signal is one of the top messaging apps today, with over 40 million active users. It is the preferred messaging app for journalists, activists, cybersecurity experts, and people who value privacy. This app has received the endorsement of high-profile figures like Jack Dorsey, Elon Musk, and Edward Snowden.

According to Signal, its goal is to protect freedom of expression. There are no ads or tracking on the app, and Signal doesn’t collect or store any data about your messages.

But is Signal safe? And how does it shield your data from prying eyes? In this article, we’ll assess how Signal protects your privacy.

An Introduction to Signal

SignalSignal is arguably the most secure messaging app today. Created by the nonprofit Signal Foundation, this app is designed to protect your privacy. It offers end-to-end encryption using its proprietary Signal protocol.

Signal is built on open-source software. Anyone can check the source code to see how the app works and if it is safe.

Signal is a fusion of two different messaging apps — TextSecure and RedPhone — created by Open Whisper Systems. This company laid the foundations for the Signal protocol and the Signal app.

Like Telegram and WhatsApp, Signal lets you send text messages, voice messages, photos, videos, GIFs, location data, and files. You can also make group calls and video calls. Signal is compatible with iOS, Windows, macOS, Linux, and Android devices.

There are no ads, affiliate links, or tracking on Signal. Also, the chat app is not affiliated with any major tech company. So, there are fewer concerns about data sharing compared to WhatsApp, which is owned by Meta (formerly Facebook).

In 2021, Signal’s monthly active users doubled after an update to WhatsApp’s privacy policy led many to believe the company would start sharing user data with Facebook.

Signal recently increased the maximum number of participants in a video call to 40 people. In comparison, you can have a video call with a maximum of eight participants on WhatsApp.

Is Signal Safe?

Why is Signal regarded as one of the most secure messaging apps? Is it really safe? We assessed the primary security features of Signal, and here’s what we found.

End-to-end encryption

Signal uses the Signal protocol for end-to-end encryption. All messages sent on the app are encrypted. Only the person you are chatting with can see your messages. Apparently, even Signal developers do not have access to your messages.

“We can’t read your messages or listen to your calls, and no one else can either. Privacy isn’t an optional mode — it’s just the way Signal works,” the company’s website reads.

Apart from your messages, Signal also encrypts your profile. Signal cannot see your profile name, image, and associated metadata. WhatsApp and Telegram can see this data.

Signal was ahead of other apps in offering end-to-end encryption for all messages. Facebook, Google, and Microsoft have all adopted the Signal protocol.

Signal security numbers

Signal assigns a security number to each chat, which allows you to verify that your conversation is secure. When you start a Signal conversation with a new contact, you can verify the security number with the other person. This is important if you’re sharing sensitive information.

You’ll receive an alert that the security number has changed if a contact switches phones or reinstalls Signal. This feature protects against man-in-the-middle attacks and eliminates the chances of hackers impersonating a contact to trick you into divulging sensitive information.

Open source

Signal is open source, so its code is accessible to the public on GitHub. Anyone can review the code. Independent researchers have reviewed Signal’s code over the years and have concluded that the app has no major security flaws.

“Signal’s mechanisms suggest a lot of effort has been invested to protect against the loss of secrets used in specific communications,” a group of academic researchers said in 2016 after analyzing the Signal protocol.

Signal is audited annually by companies and individuals. You’ll find their security audit reports here.

Signal comes with other unique security features. For example, you can lock in your phone number to ensure no one can hack your Signal account and re-register it on another device.

What Information Does Signal Collect?

Most messaging apps offer end-to-end encryption but still collect vast amounts of user data. This metadata includes information about the people you communicate with, the duration and time of each conversation, the device you are using, your IP address, phone number, and more.

Unlike other messaging apps, Signal only stores the metadata necessary for the app to work. These include phone numbers, random keys, and profile information.

Signal has reiterated its commitment to privacy over the years. In 2021, the United States Attorney’s Office in the Central District of California served Signal a subpoena, requesting personal information like users’ locations, names, and messages. The company responded that it couldn’t provide that information since it doesn’t collect it.

“It’s impossible to turn over data that we never had access to in the first place. Signal doesn’t have access to your messages; your profile name or avatar; or even the GIFs you search for,” Signal said in a blog post about the incident.

Phone number

Unfortunately, you cannot use Signal completely anonymously, as the app collects and links your personal phone number to your account — sort of like a username.

There’s a workaround if you’d like to use Signal without sharing your phone number. You can sign up with a different phone number. This could be a virtual number, a pre-paid SIM card, or a second phone number.

Contact list

Signal is a privacy-focused messaging app. But the first thing it asks when you sign up for an account is access to all the contacts on your phone. This may seem contradictory, but there’s a reason the app needs this information.

Like other messaging apps, Signal displays people in your contacts who already use the app. This way, you know who you can send messages to and call. Signal stores your contact list in an unreadable format on its servers.

You can still use Signal even if you decide not to give the app access to your contacts. You simply won’t know which of your contacts use Signal. However, people can contact you, and you can search for people with their phone numbers on Signal to contact them.

Signal and GDPR: How Can I View the Data Signal Has About Me?

Piece of paper with the text "GDPR" on itUnder the European Union’s (EU) General Data Protection Regulation (GDPR), you have the right to request a copy of the personal data that companies collect about you. Messaging services that process personal data must comply with this. While you can file a request with Signal, they can’t provide any data since they don’t collect any.

Messages, images, files, and other content sent through Signal are end-to-end encrypted. They are only readable and stored on your device. Signal doesn’t collect any information about you except your phone number.

How Does Signal Make Money?

Signal is a free encrypted communication app and contains no ads. So, how does Signal make money? Well, the app is not for profit and is fully funded by grants and donations from people who use Signal.

Unlike WhatsApp, Signal is owned by a non-profit organization. The Signal Foundation was founded in 2018 by Signal CEO Moxie Marlinspike and WhatsApp co-founder Brian Acton. The latter donated $50 million to establish the Signal foundation.

Is Signal Better Than WhatsApp?

Signal logo and WhatsApp logo with the word "VS" between them

Both WhatsApp and Signal use end-to-end encryption. This means that these chat services do not have access to your conversations. Signal also encrypts users’ profiles so it cannot access your pictures and other information in your profile. WhatsApp does not encrypt this data and therefore has access to it.

The difference between the two chat services is mainly the amount of data they collect and the companies behind them.

WhatsApp is owned by Meta (formerly Facebook), which raises some concerns about sharing data. It is unclear exactly what WhatsApp data Facebook uses for advertising.

Signal is a non-profit, privacy-friendly messaging app that does not share any information with third parties. It also does not collect any metadata — WhatsApp does. It is also worth mentioning that Signal is an open-source app which makes it more trustworthy and transparent.

In a recent interview with The Verge, Signal President Meredith Whittaker said Signal is the “most widely used, truly private messaging app on the market.”

“We go to great lengths not only to keep the contents of your messages and who you are talking to private, but to collect as little data as possible while providing a functional service. We differ from our competitors in that our mission if to provide a private app and in that we are not in any way connected to the surveillance business model,” she said.

More Privacy on Signal

While it is private by default, Signal users can further customize the privacy settings on the messaging app by:

  • Enabling expiring messages
  • Turning on app lock
  • Turning on watch prevention
  • Turning on call forwarding
  • Turning off preview images
  • Using a VPN

Make messages disappear

Even with end-to-end encryption, the messages you send via Signal will be visible on your device and the recipient’s device. This means that if either device is stolen or hacked, your messages may be exposed.

To avoid this, it is advisable to delete old Signal messages when you no longer need them. However, that does not guarantee that the recipient will do the same.

To keep your messages from staying on the recipient’s device indefinitely, enable Signal’s Disappearing Messages feature. You can set this feature for all chats or for individual contacts. You can also choose how long your messages stay before they disappear.

Enable Signal Disappearing Messages on Android or iPhone

  1. Open Signal and click on the three dots at the top left of the screen.
  2. Click on “Settings,” then tap “Privacy.”
  3. Signal screen "Settings" with the option "Privacy" highlighted
  4. In the “Disappearing Messages” section, tap “Default timer for new chats.”
  5. Signal screen "Privacy" with the option "Default timer for new chats" highlighted
  6. Select here how long messages will remain before they are automatically deleted. You can choose from the preset options or set your preferred time frame.

Note: Even if you use this feature, recipients can save your messages by taking a screenshot before they disappear.

Signal app lock

For added security, you can enable Signal’s app lock feature. When you activate this feature, you’ll need to enter your device’s password, PIN, or biometric authentication (FaceID, TouchID, or fingerprint) before you can access the app.

This security feature is not available on the desktop Signal app. You can only use it on your smartphone, and you must first have screen lock enabled on your device.

Enable Signal app lock on Android or iPhone

  1. Open Signal and click on the three dots at the top left of the screen.
  2. Click on “Settings,” then tap “Privacy.”
  3. Signal screen "Settings" with the option "Privacy" highlighted
  4. Turn on “Screen lock.”
  5. Signal screen "Privacy" with the option "Screen lock" highlighted

Protect chat from screen recordings

Signal’s screen security feature prevents other apps from taking screenshots of your messages on Signal. It also prevents Signal previews from appearing when you switch between apps. If you enable snooping prevention, Signal content will be hidden in the list of recent apps.

Enable screen security on Android or iPhone

  1. Open Signal and click on the three dots at the top left of the screen.
  2. Click on “Settings,” then tap “Privacy.”
  3. Signal screen "Settings" with the option "Privacy" highlighted
  4. Turn on “Screen security.”
  5. Signal screen "Privacy" with the option "Screen security" highlighted

Your messages are now protected from screen recordings from other apps. When switching between apps, a blue screen with the Signal logo will now appear to protect your conversations.

Enable Signal’s call forwarding

If you’re concerned about your IP address being tracked when you make calls on Signal, the call forwarding feature can help. When you activate this feature, your calls are routed through Signal’s servers, and your contact won’t be able to find out your actual IP address.

Enable call forwarding on Android or iPhone

  1. Open Signal and click on the three dots at the top left of the screen.
  2. Click on “Settings,” then tap “Privacy.”
  3. Signal screen "Settings" with the option "Privacy" highlighted
  4. Go to “Advanced” at the bottom.
  5. Toggle the switch next to “Always relay calls.” Signal will now route your calls through its servers to prevent your IP address from being revealed to the contact.
  6. Signal screen "Advanced" with the option "Always relay calls" highlighted

Turn off preview images

When you share a link on Signal and a preview image is generated, the website you refer to can also see this. The app briefly contacts that website to retrieve the preview page. The website can see that you mention them in a post and which particular webpage you mention.

Signal used to have built-in protection for this, but this feature has been removed as it didn’t work for all websites.

Turn off preview images on Android or iPhone

  1. Open Signal and click on the three dots at the top left of the screen.
  2. Click on “Chats.”
  3. Signal screen "Settings" with the option "Chats" highlighted
  4. Turn off “Generate link previews.” Now, websites can’t detect that you mention them in your message now.
  5. Signal screen "Chats" with the option "Generate link previews" highlighted

Use a VPN

Using a VPN is another way to hide your IP address. VPNs also encrypt your online traffic and protect your privacy.

In some countries with strict censorship laws, like China, Signal and other chat apps are blocked. But you can use a VPN to access Signal. You simply need to connect to a VPN server in another country to access the app.

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Conclusion: Signal Is Privacy-Friendly

Signal is one of the best privacy-friendly chat apps and an excellent alternative to WhatsApp for secure communication. It encrypts all your messages and even your profile data. It also doesn’t store any user data, and you don’t need to provide any personal information to use it.

Are you looking to secure your privacy on other social media and messaging apps? Check out these articles below:

Is Signal Safe: Frequently Asked Questions

Do you have a question about Signal? Check out the FAQ section below for quick answers to your questions. Click on a question to see the answer.

Every message you send on Signal is protected with end-to-end encryption. This means even Signal does not have access to your messages, and the company doesn’t store it. The only data Signal collects is your phone number and contacts. Check out our article on the safety of Signal to learn more.

Signal is a safer alternative to WhatsApp. Unlike WhatsApp, Signal does not collect metadata and does not share any user data with third parties. Signal also encrypts the profiles of users, while WhatsApp doesn’t.

Signal is an open-source, privacy-friendly chat app owned by the non-profit Signal Foundation. It is one of the most private messaging apps available today.

Signal has not experienced any major breach of its systems, but this doesn’t mean they’re impenetrable. In August 2022, Signal revealed that a breach of Twilio’s systems, which it relies on for SMS verification services, exposed the phone numbers and SMS codes of about 1900 Signal users.

Tech journalist
Ian is an enthusiastic content writer who loves researching and writing about cybersecurity, internet privacy and online freedom. He's a marketer and cybersecurity enthusiast who aims to educate others through his writing. During his downtime, he enjoys going on nature walks and baking sourdough bread.