Signal for Windows

Overview

Signal Private Messenger is a free, open-source chat and VoIP application maintained by the Signal Foundation, a nonprofit co-founded by Brian Acton and Moxie Marlinspike. It attracted a large number of users after privacy-related changes at WhatsApp prompted people to seek alternatives that keep conversations more private. Signal has been actively maintained and reviewed by a committed security community since its wider adoption.

Security and privacy features

Signal uses end-to-end encryption for all messages and calls so that only the sender and recipient can read the content. The app is designed to minimize stored metadata and prevent phone carriers or third parties from accessing message content. That makes it popular with journalists, public officials, and anyone who wants to reduce the risk of interception or surveillance.

Important privacy controls include:

• Two-factor authentication for added account protection
• Disappearing (self-destructing) messages that vanish after a set time
• App locking with a passcode or biometric (fingerprint) so others with access to your device cannot open Signal

Keep in mind: encryption only applies when both parties use Signal. Conversations that fall back to SMS are not end-to-end encrypted.

What you can send and group limits

Signal supports a variety of message types and conversation formats:

• Photos, videos, links and voice recordings
• Group chats with support for up to 150 members
• Admin controls for managing group membership and settings

You can sync your contacts in the app to see who already uses Signal. If someone you want to reach isn’t on Signal yet, you can invite them through several methods:

• Share an invite link
• Post or send an invite via social networks
• Send an invitation by SMS

Transparency and code auditing

Signal’s source code is publicly available. While some users worry that open code could expose vulnerabilities, the Foundation and many security researchers argue that transparency allows independent audits and faster discovery and patching of bugs. Public code helps outside experts verify claims about how the app handles encryption and data.

Practical privacy tips

• If you or your colleagues prefer not to expose a personal phone number, you can register with a Google Voice number or other secondary number when creating an account.
• iOS users who do not want call or message metadata synced to iCloud can disable that feature in Signal’s settings on mobile and desktop.
• Remember that other messaging platforms such as Apple Messages, Telegram and WeChat also offer privacy or security features; requirements and guarantees differ between apps.

Who should consider using Signal

Signal is well suited for:

• People handling sensitive information who need strong safeguards against eavesdropping
• Privacy-conscious everyday users who want to limit data collection by platforms or carriers
• Those who prefer software with open-source code and independent security review

Limitations and final notes

Signal focuses on privacy and secure communication rather than flashy customization. It has fewer theme and sticker options than some mainstream apps, but excels at protecting user data. For secure communication between parties that have Signal installed, it remains one of the most robust, widely recommended options.