What is RCS? How is it different from SMS and iMessage?

There’s been an ongoing battle between messaging services for years. Despite Google’s many attempts, there has been no real messaging competitor capable of competing with Apple’s iMessage.

Google has been pushing for another common standard: RCS. The standoff between the tech giants has been quite public, with Google repeatedly prodding Apple and Apple refusing to support RCS for years. Then, Apple made a change on November 16, 2023, saying that it would support RCS in 2024. A moment of unity for cross-device messaging seems to be coming.

Since Verizon adopted Google’s RCS protocol in February 2024, all Android phones and major US mobile carriers now support RCS messaging. But what exactly is RCS, what capabilities does it have, and what devices can it be used on?

What is RCS?

The future of text messaging is here…sort of.

Rich Communication Services (RCS) is an agreement between mobile operators and phones. The overall goal of RCS is to replace SMS and MMS messaging, formats we are all familiar with because they have been around for many years. RCS messaging is very similar to WhatsApp, with live chat possible, including multimedia support, and everything is handled over the data network.

This means RCS messages can carry more information, so users can send each other things like full-resolution photos, videos, and audio messages.

RCS Messaging’s biggest advantage over SMS – and the reason it was implemented in the first place – is that it improves the SMS/MMS messaging experience, much in the same way as iMessage. This means RCS messages can carry more information, so users can send each other things like full-resolution photos, videos, and audio messages. Typing indicators and read receipts are also part of RCS messaging, something users are sure to appreciate.

Users can video call each other directly within the messaging app without having to rely on third-party software. Group messaging is possible, and little things like read receipts and indicators showing other users typing messages are also included. RCS messages also remove the current 160-character limit in SMS messages.

Businesses can use RCS Messaging to send things like airline boarding passes, package delivery notifications, and credit card fraud alerts.

Is RCS encrypted and secure?

Short answer: Yes, it’s end-to-end

Google Messages uses end-to-end encryption to ensure conversations between senders and recipients remain private. Your conversation is encrypted using a key that only any one participant can access. You can do this by looking for a lock icon next to the message timestamp, looking for a banner in the thread that shows the lock icon along with the participant’s name, or looking for a lock icon on the send button.

If you want to confirm that your conversation is private, you can follow the instructions listed here by Google to confirm the verification code with a specific contact in the Messages app.

Which phones and carriers support RCS?

RCS is almost universal

In the US, the major US carriers – Verizon, AT&T, Sprint and T-Mobile – have agreed on an RCS cross-carrier solution in an initiative called CCMI (Cross-Carrier Messaging Initiative), and we now have RCS in Available and interoperable worldwide (except Russia). At Google I/O 2023, Google said there were more than 800 million monthly RCS users.

If you send an RCS message to someone whose phone or mobile network does not support RCS messages, the message will be sent as a regular text message.

Does iPhone support RCS messages?

RCS finally comes to iPhone in 2024

Apple announced that it will support the GSMA common profile for RCS on iPhone by the end of 2024. Apple’s announcement that it will support RCS means Google Messages and Apple iMessage may work together, so it’s possible that by the end of the year, iPhone and Android users will have rich messaging across platforms. It remains to be seen how widespread RCS support will be in iMessage, and what the experience will be like when supporting Android Messages, but we hope to learn more after the opening keynote at WWDC 2024 on June 10.

The main reason for Apple’s adoption of RCS may have less to do with Google and more to do with growing pressure from the European Union, which ruled that messaging apps need to work together under the Digital Markets Act.

Apple has been under pressure to support RCS for years. Google mocked Apple, with executives issuing statements about how RCS would make all devices work better and more securely together. As this video shows, Google is really working on this.

The problem is, especially for US users, iMessage dominates, and there’s some tension between the blue and green bubbles. iMessage bubbles are green, and default SMS bubbles are blue. When Android users send messages, their colors are different from the colors of messages sent between iPhone users. There was a lot of social commentary surrounding this, bordering on discrimination. But that could all end in 2024.

The main reason for Apple’s adoption of RCS may have less to do with Google and more to do with growing pressure from the European Union, which ruled that messaging apps need to work together under the Digital Markets Act.

How to check if my phone supports RCS?

It should be turned on by default, but you can turn it on manually

First, if you’re an Android user, you should use the Google Messages app and make sure it’s the default messaging app (although other apps will support it, Google’s approach means you’ll need to use your own app).

1. Open the app and click on the menu in the upper right corner.
2. choose message set up.
3. choose RCS cat.
4. RCS chat will tell you if support is available and if it’s enabled.

When you sign in to a new phone and open Google Messages for the first time, you’ll be asked if you want to enable RCS Messages. If not prompted, you can follow the instructions above to turn it on. In the same menu, you can also find other options such as controlling typing indicators and read receipts. Note that you need wireless or cellular data to send RCS messages, so if you can’t send RCS messages, you also have the option of sending SMS.

If you’re an iPhone user, the current answer is that you don’t have access to RCS messaging and you’ll need to wait until Apple officially adds support – something we expect to see in iOS 18 later this year.