It’s a common question because people see RCS, iMessage, WhatsApp, and Signal all described as “encrypted messaging” and assume they interoperate. They don’t. New to RCS itself? Start with what is RCS messaging. Here’s the precise answer about Signal — and why it works this way.
Why Signal Doesn’t Support RCS
There are two reasons, one technical and one philosophical. Technically, Android does not provide an RCS API that third-party apps can use — RCS is handled by the designated native client (Google Messages), so even if Signal wanted to add RCS, there’s no supported way for an outside app to send and receive it. Philosophically, Signal’s entire model is a single, consistent, end-to-end-encrypted network: every message and call runs through the Signal Protocol, and the organisation behind it doesn’t harvest conversation metadata. Mixing in RCS (a carrier-dependent protocol with different security properties) would break that guarantee. So Signal’s answer has consistently been to keep everything inside Signal rather than bridge to other networks.
Signal Doesn’t Do SMS or MMS Either
This surprises long-time users: Signal used to support SMS on Android, but that functionality was removed. Per Signal’s own support guidance, you cannot send or receive SMS or MMS with Signal — all communication through Signal is private, and both you and your contact need to be on Signal to message each other. So Signal isn’t a universal texting app at all; it’s a private network you opt into. That’s a deliberate design choice, not a missing feature.
Signal vs RCS: How They Differ
Signal | RCS (business & personal) | |
|---|---|---|
What it is | Standalone encrypted app + network | Carrier-based successor to SMS |
Who can receive | Only other Signal users | Anyone with RCS on a supported device/carrier |
Encryption | Always E2EE (Signal Protocol) | P2P E2EE since 2026 where supported; business RCS uses verified identity |
Needs an app? | Yes — install Signal | No — built into the native messaging app |
Business messaging | No A2P/business channel | Yes — verified, branded, rich (RBM) |
The key distinction: Signal is an app you and your contacts choose; RCS is built into the phone’s default messaging and reaches anyone whose device and carrier support it. For businesses, that reach plus verified branding is exactly why RCS matters — see how RCS is changing brand messaging.
Does RCS Encryption Change This?
In May 2026, Apple and Google began rolling out cross-platform end-to-end encryption for person-to-person RCS between iPhone and Android (built on the GSMA Universal Profile and the MLS protocol, enabled by default where the OS versions and carriers support it). That’s a big step for RCS privacy — but it doesn’t make Signal support RCS, and it doesn’t make RCS the same as Signal. RCS still runs through the native client, not third-party apps, and privacy researchers note RCS still exposes more metadata than Signal does. So even in 2026, Signal remains a separate, opt-in encrypted network — not an RCS client.
Which Should You Use?
It depends on the goal. For maximum private messaging with people who also use it, Signal is the stronger choice. For everyday texting that just works with anyone — now with cross-platform encryption where supported — RCS through your native app is the practical default. And for businesses wanting to reach customers with verified, branded, interactive messages at scale, neither Signal nor consumer chat applies — that’s business RCS (RBM), which you run through an RCS partner.
Conclusion
Signal does not support RCS — or SMS or MMS. It’s a standalone, end-to-end-encrypted network where both parties must use Signal, and Android doesn’t expose an RCS API for third-party apps anyway. The 2026 arrival of cross-platform RCS encryption improved RCS privacy but didn’t change Signal’s position: it remains its own opt-in network, not an RCS client. Choose Signal for private chats, RCS for universal texting, and business RCS for reaching customers at scale. For the channel basics, see what is RCS messaging.
FAQs
Does Signal support RCS?
No. Signal cannot send or receive RCS. It’s a standalone encrypted network, and Android doesn’t provide an RCS API for third-party apps — RCS runs through the native messaging client instead.
Can Signal send SMS or MMS?
No. Signal previously supported SMS on Android but removed it. Today it cannot send or receive SMS or MMS — both you and your contact must use Signal to message each other.
Is RCS as secure as Signal?
Person-to-person RCS gained cross-platform end-to-end encryption in 2026 where supported, but it still exposes more metadata than Signal, and business (A2P) RCS isn’t E2EE. Signal remains the stronger choice for private messaging.
How do I message someone over RCS?
Use your phone’s native messaging app — Google Messages on Android or Apple Messages on iPhone — with RCS enabled and carrier support on both ends. You don’t use a third-party app like Signal for RCS.
Why did Signal remove SMS?
To keep all communication inside its private, encrypted network. Mixing in unencrypted SMS (or carrier-dependent RCS) would undermine the consistent privacy guarantee Signal is designed around.
