Signal vs WhatsApp
Two messengers that make free voice calls to other people running the same app, and neither of which can dial an ordinary telephone number. The choice is about ownership, retention and reach — not about price, because both are free.
vs
Neither can call a telephone number. Both reach only other installs of themselves, so if the person you want to speak to has no smartphone, will not install an app, or is on a landline, this comparison is the wrong one — a service that dials real numbers is what you need.
Between the two: WhatsApp reaches more people than any other app on earth, which is the only argument that matters for a communication tool. Signal is run by a non-profit foundation, funded by donations rather than by a platform business, and collects dramatically less about who talks to whom. Both require a phone number to register. Pick Signal on principle, WhatsApp on reach, and accept that most people end up with both.
Side by side
Pick what you care about and the differences reorder.
1 of 8 fields differ; 6 are the same.
How to read this comparison
Work down in this order and most comparisons resolve in under a minute. First, can it reach the number you actually need — a service that only calls its own users is not a cheaper version of one that dials a landline, it is a different thing. Second, what are the billing terms: the unit a call is measured in, and whether a fixed fee is added to each one. Third, what happens to money you do not spend.
The per-minute rate is deliberately not the first question here, and it is the only question most comparisons ask. At the same advertised rate, a service that rounds every call up to a whole minute and adds a per-call fee can cost close to double another on the short calls that make up most people's actual usage. The rate is the number that gets compared because it is the number that gets published.
Where they actually differ
Platforms
Signal runs on iOS, Android, Windows, macOS, Linux. WhatsApp runs on iOS, Android, Web, Windows, macOS. This decides more comparisons than it ought to: a service that is excellent and unavailable on the device in your hand is not a candidate at all, and a desktop client matters more than it sounds when the alternative is holding a phone against your ear for an hour.
Where they are the same
- Calls a phone number: both only reaches its own users.
- Billing unit: both app to app only.
- Connection fee: both none.
- Credit expiry: both never.
- Subscription: both no subscription.
- Account required: both account required.
What each one is
Signal
Signal is an end‑to‑end encrypted messaging app that supports secure text messaging, voice and video calls, and media sharing between Signal users; it does not provide calling to regular phone numbers via PSTN tariffs.
WhatsApp is a cross‑platform messaging and VoIP app that provides end‑to‑end‑encrypted text messaging, voice and video calls, and media sharing between users over the internet, but does not offer PSTN calling to regular phone numbers.
How each one bills you
As published by Signal
- none
- No calling credit is used; Signal is donation‑supported and uses internet data only.
- $0 (donation‑supported, no subscription required).
As published by WhatsApp
- none
- No calling credit is used for consumer WhatsApp; usage depends on internet connectivity provided by the user’s operator or Wi‑Fi.
What each one asks of you
As published by Signal
Users register with a mobile phone number, receive an SMS or call for verification, and then can use Signal across devices (linked desktop clients).
As published by WhatsApp
Registration requires a mobile phone number for SMS or call verification; the number serves as the primary account identifier.
Plans, where each one sells them
As published by Signal
Signal is provided for free by the non‑profit Signal Foundation; no recurring subscription or per‑minute call charges apply for app‑to‑app usage.
As published by WhatsApp
Consumer app has no in‑app subscription for calling; WhatsApp Business is also free to download, with business API usage billed separately by Meta partners.
Published rates
The corridor prices each provider published at the time of the research. An empty list means the provider does not publish its rates outside its own app, which is itself worth knowing before you top up.
Signal
Signal publishes no per-country rates outside its own app.
Source, as recorded: Signal documentation and app‑store descriptions; no PSTN outbound calling feature is provided.
WhatsApp publishes no per-country rates outside its own app.
Source, as recorded: WhatsApp consumer apps do not provide paid PSTN calling; calls are app‑to‑app over data.
What each one does
Signal
- End‑to‑end encryption for all messages and calls by default using the Signal Protocol.
- Supports one‑to‑one and group voice and video calls.
- Open‑source client and protocol, with publicly available code for auditing.
- Minimises metadata collection, with the foundation claiming to retain almost no data about users or their contacts.
- Desktop apps linked to a primary mobile device allow multi‑device usage.
- Supports disappearing messages with configurable timers.
- Operated by the non‑profit Signal Foundation, funded through donations rather than advertising.
- Available globally via major app stores without monthly fees.
- Provides end‑to‑end‑encrypted messaging and voice/video calls between WhatsApp users.
- Supports group chats and group voice/video calls (up to 32 participants on mobile as per recent app descriptions).
- Available on mobile apps, WhatsApp Web, and desktop clients, with chats synced across devices.
- Uses phone numbers as identifiers, eliminating separate usernames.
- Offers free international messaging and calls over data without per‑minute charges from WhatsApp itself.
- Owned and operated by Meta Platforms, Inc.
- WhatsApp Business app adds business‑oriented messaging tools while using the same underlying calling and messaging infrastructure.
- As of 2020 it had more than 2 billion active users worldwide, and remains one of the most widely used messaging apps globally.
What users complain about
Signal
- Some users and organisations find phone‑number‑based registration limiting or privacy‑sensitive despite Signal’s design.
- Signal’s user base (roughly tens of millions of monthly users) is smaller than major messaging competitors, which can limit network effects.
- Certain governments have intermittently blocked or throttled Signal, causing connectivity problems in those regions.
- Some reviewers express concerns about metadata and data sharing with parent company Meta, despite message content being end‑to‑end encrypted.
- Enterprise and privacy‑focused reviewers sometimes criticise limited multi‑device independence, as a phone number and device are still central to account setup for most users.
- Crowded chats and high message volume can make long‑term conversation management difficult according to user reviews on app‑analysis sites.
About each company
| Founded | 2014 (Signal protocol and app evolved from TextSecure/RedPhone; the Signal Foundation was created in 2018). | 2009 |
|---|---|---|
| Headquarters | San Francisco Bay Area, United States (Signal Foundation; incorporated in the US). | Menlo Park, California, United States (under Meta Platforms). |
| Users | Estimated 40–70 million monthly users according to media reports. | Over 2 billion active users worldwide as of 2020; remains one of the most‑used messaging services globally. |
| Store rating | High‑4‑star rating on Google Play according to app descriptions; exact rating and review count vary across regions. | 4.7 (Google Play developer page aggregate rating, hundreds of millions of reviews). |
| Minimum purchase | $0 (donation‑supported, no subscription required). | — |
If neither of them fits
Both of the services above bill per minute or cannot dial a phone at all. If what you need is to call an ordinary number and pay only for the seconds you talk, that is what we publish — and the same nine fields are in the table above, in the first row, marked as ours.
Rates from $0.03 a minute across 41 destinations, billed per second with no connection fee and credit that does not expire.
What Telvio does and does not doSources and dates
Every value on this page is quoted from the provider's own published material, gathered in a structured research pass on 2026-03-18. Where a provider published no answer, the page says so rather than estimating. Nothing here is a review: call quality, reliability and support are not assessed, because they cannot be established from published material.
Bottom line
Both are free, both call only other users of the same app, and both require your phone number to sign up. Neither reaches a landline or a mobile that has not installed it.
WhatsApp wins on reach — over two billion users, which means the person you want is probably already there. Signal wins on data: a non-profit publisher, donation funded, and far less metadata retained.
If the person you need to reach will not install anything, neither of these is the answer. That is what a service that dials ordinary telephone numbers is for.
Frequently asked questions
Can Signal call a landline or mobile number?
No. Signal reaches only other installs of itself, so it cannot call a landline or a mobile belonging to somebody who has not installed it.
Can WhatsApp call a landline or mobile number?
No. WhatsApp reaches only other installs of itself, so it cannot call a landline or a mobile belonging to somebody who has not installed it.
Does Signal charge a connection fee?
No separate connection fee is published for Signal, so the cost of a call is the per-minute rate applied to the billed time.
Does WhatsApp charge a connection fee?
No separate connection fee is published for WhatsApp, so the cost of a call is the per-minute rate applied to the billed time.
Does unused credit expire on Signal or WhatsApp?
Credit on Signal does not expire according to its published terms. Credit on WhatsApp does not expire according to its published terms. Expiry costs most when you top up in large amounts and call infrequently.
Which is cheaper for short calls, Signal or WhatsApp?
Neither publishes per-country rates in a form that allows a like-for-like table, so the comparison rests on billing terms. Signal bills app to app only, WhatsApp bills app to app only. On calls of under a minute the billing unit and any per-call fee change the total more than the headline rate does.
Do Signal and WhatsApp require an account?
Signal: Account required. WhatsApp: Account required. Every service in this comparison set except one requires you to identify yourself before you can call.
Which devices do Signal and WhatsApp run on?
Signal runs on iOS, Android, Windows, macOS, Linux. WhatsApp runs on iOS, Android, Web, Windows, macOS. These are the platforms each provider publishes.
