Why Signal Is the Only Messaging App Privacy Experts Use (And How to Set It Up)

If you ask any security researcher, privacy advocate, or intelligence professional which messaging app they use for personal conversations, the answer is almost always the same: Signal. Not WhatsApp. Not Telegram. Not iMessage. Signal.

This is not tribalism or brand loyalty. It is a technical assessment. Signal does things that no other mainstream messaging app does — and the things it does not do are equally important.

What Makes Signal Different

End-to-End Encryption by Default

When you send a message on Signal, it is encrypted on your device before it leaves, and it can only be decrypted on the recipient's device. Signal's servers never see the content of your messages. Not even Signal (the organization) can read them.

WhatsApp also uses end-to-end encryption (they actually licensed Signal's protocol), but there is a critical difference: WhatsApp backs up your messages to Google Drive or iCloud by default, and those backups are not encrypted. So your messages are encrypted in transit but sitting in plaintext on a cloud server. WhatsApp introduced encrypted backups as an option in 2021, but it is not the default and most users never enable it.

Telegram is worse. Telegram does not use end-to-end encryption by default. Regular Telegram chats are encrypted between your device and Telegram's server, but Telegram can read them. You have to manually start a "Secret Chat" to get end-to-end encryption, and Secret Chats do not work for group conversations. Most Telegram users are having conversations that Telegram's servers can access.

iMessage uses end-to-end encryption and has improved significantly. But it only works between Apple devices, it stores messages in iCloud (which Apple can access under court order unless you enable Advanced Data Protection), and it is closed source — you are trusting Apple's claims without the ability to verify.

Minimal Metadata Collection

Encryption protects what you say. But metadata — who you talk to, when, how often, from where — can be just as revealing. If someone knows you messaged a divorce lawyer at 11pm, then a real estate agent the next morning, they know a lot about your life without reading a single message.

Signal collects almost no metadata. In 2021, Signal was subpoenaed by a federal grand jury, and their response was remarkable: the only information they could provide was the date the account was created and the last date the account connected to Signal's servers. No contacts, no groups, no message history, no location data. They did not have it.

WhatsApp, by contrast, collects and shares extensive metadata with Meta (Facebook): your phone number, contacts, usage patterns, device information, location data, and more. This metadata feeds Meta's advertising machine. Your message content may be encrypted, but your behavior is not.

Open Source and Independently Audited

Signal's code is open source — anyone can review it, audit it, and verify that it does what it claims. This is not a small thing. Closed-source encryption requires you to trust the company. Open-source encryption lets you verify.

Signal's protocol has been formally audited by independent security researchers and is widely regarded as the gold standard for secure messaging. The same protocol powers WhatsApp's encryption, which tells you something about its quality.

Funded by a Nonprofit

Signal is developed by the Signal Foundation, a 501(c)(3) nonprofit. They do not sell ads, do not sell data, and do not have shareholders demanding growth. The app is funded by donations.

This matters because the business model determines the incentives. WhatsApp's business model requires your data. Telegram's business model is evolving toward ads and paid features. Signal's only obligation is to its users and its mission.

How to Set Up Signal Properly

Setting up Signal takes about 10 minutes. Here is how to do it right.

Step 1: Download Signal

• iPhone: App Store, search "Signal"
• Android: Google Play Store, search "Signal"
• Desktop: signal.org/download (Windows, Mac, Linux)

The desktop app requires a phone app to set up — you cannot use Signal on desktop without first activating it on your phone.

Step 2: Register with Your Phone Number

Signal uses your phone number as your identifier. This is the one privacy trade-off: anyone who has your phone number can find you on Signal. There is no username-based discovery (though Signal has been rolling out usernames as an alternative).

If this concerns you, consider registering Signal with a secondary phone number (a prepaid SIM or Google Voice number).

Step 3: Set a PIN

Signal will ask you to create a PIN. This PIN encrypts your account data (contacts, profile) so that if Signal's servers were ever compromised, your information is protected. Choose a strong PIN — at least 6 digits, ideally alphanumeric.

Step 4: Change These Settings

Open Signal's settings and make these adjustments:

Privacy settings:

• Screen lock: ON (requires biometric or PIN to open Signal)
• Screen security: ON (prevents screenshots of Signal conversations and hides content in the app switcher)
• Incognito keyboard: ON (prevents your keyboard from learning what you type in Signal)
• Read receipts: Your choice, but OFF for maximum privacy
• Typing indicators: OFF for maximum privacy

Disappearing messages:

• Set a default timer for all new conversations. We recommend 1 week or 4 weeks as a starting point. This means messages automatically delete after the timer expires — on both your device and the recipient's.
• You can override this for specific conversations (longer for important threads, shorter for sensitive ones).

Notifications:

• Show: "Name Only" or "No Name or Message" to prevent message previews from appearing on your lock screen.

Storage:

• Review message storage settings. Signal stores messages locally on your device — they are not backed up to iCloud or Google Drive by default (which is a good thing for privacy, but means you lose messages if you lose your phone).

Step 5: Set Up Desktop (Optional)

On your computer, download Signal Desktop from signal.org/download. Open it, and it will show a QR code. On your phone, go to Signal > Settings > Linked Devices > Link New Device, and scan the QR code.

Desktop is convenient for longer conversations but adds another device that stores your messages. If your computer is not secured (no disk encryption, no screen lock), desktop Signal creates an additional risk surface.

Step 6: Invite Your Contacts

Signal only works if the people you talk to also use it. The good news: Signal makes this easy. When you open a new message, Signal shows which of your contacts are already on Signal. Start there.

For everyone else, the pitch is simple: "I am switching to Signal for messaging. It is free, it works just like texting, and it is more private. Here is the link: signal.org."

Do not try to explain the cryptographic protocol. Just tell them it is more private and works the same way.

Signal vs. WhatsApp vs. Telegram: The Real Comparison

| Feature | Signal | WhatsApp | Telegram |

|---------|--------|----------|----------|

| E2E encryption (default) | Yes, always | Yes, messages | No (opt-in only) |

| E2E encryption (groups) | Yes | Yes | No |

| Backup encryption | No cloud backups | Optional (off by default) | No E2E for cloud |

| Metadata collection | Almost none | Extensive (shared with Meta) | Moderate |

| Open source | Yes (client + protocol) | No (protocol only) | Partially (client only) |

| Funding model | Nonprofit donations | Meta (advertising) | Ads + premium |

| Disappearing messages | Yes (default timer available) | Yes | Yes (Secret Chats only) |

When Signal Is Not Enough

Signal is the best mainstream messaging app for privacy, but it is not a complete privacy solution. Your privacy also depends on:

• Your email: If your email provider can read your emails, that is a major privacy gap. Consider Proton Mail for encrypted email.
• Your phone itself: If your phone is compromised (malware, spyware), Signal's encryption does not help — the attacker can read messages on your screen.
• Your contacts: Signal protects messages in transit and at rest on your device. But the person you are messaging can screenshot, forward, or share your messages. Trust in the recipient is always required.

Key Takeaways

• Signal is the only mainstream messaging app that is end-to-end encrypted by default, open source, nonprofit-funded, and collects minimal metadata.
• WhatsApp uses Signal's encryption protocol but collects and shares extensive metadata with Meta, and cloud backups are unencrypted by default.
• Telegram does not use end-to-end encryption by default — most Telegram conversations can be read by Telegram's servers.
• Set up Signal with screen lock, screen security, disappearing messages, and notification privacy enabled.
• Signal works on iPhone, Android, Windows, Mac, and Linux — it can replace your default messaging app for most conversations.
• Privacy is a system, not a single app. Pair Signal with encrypted email (Proton Mail) and good device security for comprehensive protection.

The switch takes 10 minutes. The privacy improvement lasts as long as you use it. Install Signal today, change the settings described above, and start moving your important conversations there.

Affiliate Disclosure: This article may contain affiliate links. If you make a purchase through these links, we may earn a small commission at no extra cost to you. We only recommend products we genuinely believe in. This helps support our work and allows us to continue providing free content.