Description: Signal is a secure messaging app designed to provide end-to-end encrypted communication, allowing users to send messages, make voice and video calls, and share files while maintaining privacy and security.
Status: Active
Core Features and Compatibility
Core Features: End-to-End Encrypted Messaging, Voice and Video Calls, Group Chats, Media and File Sharing, Disappearing Messages, Screen Security, Registration Lock.
Operating Systems: Android, macOS, iOS, Windows, Linux
Offline Functionality: ⚠️
Mobile Support: ✅
Languages Supported: 68 languages
Technical Level: Beginner
Security and Privacy
Security Features: End-To-End Encryption, Encrypted Group Chats, Disappearing Messages, Screen Security, Registration Lock, No Ads or Trackers, Open Source Code, Encrypted Attachments, Incognito Keyboard (Android), Relay Calls, 2 Factor Authentication, ZRTP
Data Collection Level: Minimal
Security and Privacy Rating: ⭐⭐⭐⭐⭐ (5.00)
Deployment and Technical Details
Deployment Architecture: A service with a local client that’s hosted by a third party - You install a client on your device, but it connects to and depends on a remote server (e.g., install app (client), but servers handle message relaying, etc.).
License: GNU Affero General Public License v3.0
Cost: Fully Free
Maintenance and Support
Maintenance Status: Publicly available update logs in appstore. Development team responds within anywhere from an hour to a day. Funding and Sponsorship include donations from individuals and over $22,000,000 dollars in 2023.
Community Support: ✅
Maintenance and Sustainability Rating: ⭐⭐⭐⭐⭐ (5.00)
Limitations and Vulnerabilities: Signal operates using centralized servers, which are necessary to manage encrypted communication and ensure secure message delivery. However, for enhanced privacy, Signal does not offer cloud backup options—meaning users must manually transfer data when switching devices. Its strong end-to-end encryption contributes to slightly higher bandwidth usage compared to less secure messaging apps. Additionally, due to its emphasis on privacy and encryption, Signal may be blocked or restricted in certain countries where governments impose tight controls on secure communication tools.