Signal
publishedEnd-to-end encrypted messaging with minimal metadata
A messaging app built by a nonprofit foundation. End-to-end encryption for all messages by default. Minimal metadata collection. Open source client and server. Funded by donations, not data.
Trust Surface
Interoperability
UX & Feed
Business Model
Quick Facts
| RSS | Not available |
| Federation | no |
| API | Not available |
| Chronological Feed | yes |
| Algorithmic Feed | na |
| Deletion | yes |
| Open Source | yes |
| Moderation Transparency | partial |
Why It Belongs
Why It Belongs Here
Signal sets the standard for private messaging. The Signal Protocol (used by WhatsApp, Google Messages, and others) was designed here. Unlike its adopters, Signal collects virtually no metadata — not even who you talk to.
The nonprofit structure (Signal Foundation) means no investors demanding growth-at-all-costs. Revenue comes from donations.
Tradeoffs
Tradeoffs
- Phone number required: Registration requires a phone number, which is a privacy concern for some users
- No federation: Centralized service, no interoperability with other messaging platforms
- Limited export: Message history export is partial and platform-specific
- No web client without phone: Desktop apps require the phone app to set up
- Feature velocity: Slower feature development compared to commercial competitors
Claims (4)
End-to-end encryption is on by default for all messages — no opt-in required.
Signal collects minimal metadata — does not store who you communicate with.
Phone number requirement creates a linkability vector that undermines anonymity.
Nonprofit structure (Signal Foundation) aligns incentives with user privacy over profit.
Evidence (4)
Signal Support: E2E encryption on by default, no unencrypted mode
strong"Privacy isn't an optional mode — it's just the way that Signal works." All messages, calls, video calls, Stories, and profiles are E2E encrypted by default using the Signal Protocol. After removing SMS support on Android (2023), there is no unencrypted mode. Post-quantum SPQR enhancement announced October 2025.
Signal Big Brother: 7 government requests, only creation date + last connection provided
strongSignal's transparency page documents 7 government requests (2016-2026). In every case, Signal could only provide: (1) Unix timestamp of account creation, (2) date of last connection. Cannot provide messages, chat lists, groups, contacts, profiles. March 2026 DC grand jury subpoena for 37 phone numbers received same minimal response.
Signal usernames (Feb 2024): phone numbers hidden by default, but still required for registration
strongFebruary 2024: Signal launched usernames. Phone numbers now hidden by default from people who don't have them in contacts. Users can set usernames to be discovered without sharing their number. However, phone number is STILL REQUIRED to register — cannot create account without one.
ProPublica: Signal Foundation 990 filings — $29.4M revenue, -$8.6M net, sustained by Acton loan
strongSignal Technology Foundation (501(c)(3)) 2024 filing: Revenue $29.4M (74% contributions, 22% program services). Expenses $38.0M. Net assets -$4.7M. Original $105M loan from Brian Acton (2018) at 0% interest, due 2068, being forgiven ~$10-30M/year. Spending exceeds revenue; sustainability remains an open question.