Signal vs RCS: an Honest Comparison

Published: October 7, 2026 · Updated: October 8, 2026

RCS has been marketed as the upgrade that finally fixes texting. And in some ways it does: typing indicators, read receipts, big photo and video sharing, all inside the default messaging app on most Android phones. Google then added end-to-end encryption on top, and headlines declared the privacy problem solved. The reality is more complicated, and the complications all point the same direction: RCS encryption is conditional, and privacy that only works sometimes is not privacy you can rely on.

Signal and RCS, side by side

The table's most important row is the fallback row. Everything else is a detail; the fallback is the structural flaw.

What RCS actually is

RCS stands for Rich Communication Services. It is not an app and not a company. It is a standard, agreed between mobile carriers, for what texting should have become after SMS: modern messaging with all the features people expect. Google took that standard, built it into its Messages app, and pushed carriers to support it, which is why most Android phones today do RCS out of the box.

This history matters because it explains every limitation below. RCS was designed by carriers, for carriers, in a world where encryption was an afterthought. Google bolted end-to-end encryption onto its own implementation afterward. That is genuinely better than nothing, and Google deserves credit for doing it. But a bolted-on feature inside a carrier standard will never have the guarantees of a system designed around encryption from the start.

It also matters because "RCS" means different things on different phones. Google Messages on Android does Google's version. Samsung's app does its own thing in some regions. iPhones now speak RCS too, but Apple's implementation and Google's implementation do not share Google's encryption layer. When someone says "RCS is encrypted," always ask: which RCS, between which apps, in which chat?

The encryption gap: where RCS protection stops

Google's end-to-end encryption for RCS uses the Signal Protocol, the same cryptography family Signal itself uses. That is a serious, well-regarded foundation. The problem is not the math. The problem is the coverage.

One-to-one only

Google's RCS encryption applies to direct conversations between two people. Group chats are excluded. In a group RCS chat, Google and the carriers handle your messages without end-to-end protection. Given how much of real life happens in groups, family groups, friend groups, work groups, this is a large hole, not a small one.

Google Messages to Google Messages only

The encryption is Google's proprietary layer on top of RCS. It works when both people use Google Messages. Chat with someone on a different RCS app, or with an iPhone, and the encryption does not apply. There is no interoperable standard here: Google's encryption is a Google feature, not an RCS feature. Our Signal vs iMessage comparison covers the iPhone side of this gap.

Carrier and region dependent

RCS itself needs carrier support to work at all, and that support is uneven around the world. Where RCS is not supported, or where it glitches, the conversation drops to SMS. Which brings us to the real problem.

You cannot verify it

Google's implementation is closed. There are no safety numbers to check, no open code to audit, no way for you to confirm that the person you are talking to is really who the app says they are. You are trusting Google, the carrier, and the whole chain in between. Compare that with how Signal's encryption works, where verification is a built-in ritual, not a leap of faith.

The SMS fallback problem

Here is the scenario that breaks every "RCS is encrypted" claim: you are chatting with someone, the RCS connection drops, and your app silently sends the next messages as SMS. SMS has no encryption. None. Your messages travel as plain text through carrier systems, readable by the carrier, interceptable over the air with the right equipment, and stored God-knows-where.

This is not a rare edge case. It happens when the other person loses data coverage, when RCS provisioning glitches (which it does, regularly), when you message someone whose carrier never enabled RCS, and when you roam onto networks that do not support it. Each time, the app is supposed to warn you. Warnings are small, easy to miss, and easy to tap through. Most people have no idea which of their "text messages" went out encrypted and which went out naked.

Signal has no fallback because Signal has nothing to fall back to. A Signal message either goes through encrypted or it does not go. That all-or-nothing design is the entire point. Conditional privacy, privacy that quietly downgrades itself when conditions change, trains users to assume protection they do not have. The green "RCS" label in your messaging app does not tell you whether this particular message, to this particular person, right now, is actually encrypted. And that uncertainty is the vulnerability.

Why "RCS is encrypted now" does not replace Signal

Partial encryption vs total encryption

Put the pieces together and the picture is clear. RCS encryption is real but partial: 1:1 only, Google Messages only, carrier-dependent, unverifiable, and one glitch away from SMS. Signal's encryption is total: every chat, every group, every call, every platform, verifiable, with no fallback to anything weaker.

Who you are trusting

There is also the question of who you are trusting. Google is an advertising company. Its RCS encryption protects message content from outsiders, which is good. But your messaging metadata, who you talk to, when, how often, lives inside Google's systems under Google's privacy policy. It feeds the same profile Google builds from your search, your location, and your email. Signal's nonprofit structure means there is no profile to feed. Our Signal metadata guide explains exactly how little Signal keeps.

RCS is still a genuine upgrade over SMS

None of this means RCS is useless. For ordinary texting with people who will never install another app, RCS is a genuine upgrade over SMS: better media, better group handling, and encryption in the best case instead of never. Use it and enjoy it. Just do not confuse "better than SMS" with "a private messenger." The distance between those two is the distance between this page's two columns.

Be honest about the threat model

And be honest about the threat model. If your concern is a nosy carrier or a thief with a radio scanner, RCS encryption in the best case helps. If your concern is a government request, a compromised carrier, or Google's own data collection, only the best case helps, and you will rarely know whether you are in it. Signal removes the question entirely.

Who should use which

The two are not enemies. Plenty of people use RCS for everyday texting and Signal for conversations that matter. What you should not do is look at the little lock icon in Google Messages and conclude the privacy problem is solved. It is improved. Solved is a different word.

If Signal is your pick and the Play Store is not on your phone, grab the verified build straight from the source: our Signal APK download guide walks through it, and the current website build is version 8.29.3.

Frequently asked questions

Related guides

• All Signal comparisons: the full compare hub
• Signal vs iMessage: the iPhone side of the RCS gap
• Signal vs WhatsApp: our in-depth WhatsApp comparison
• How Signal encryption works: verifiable encryption explained
• Signal metadata guide: how little Signal keeps