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RCS vs. SMS vs. iMessage: What's the difference?

Google Messages And Imessage Icons
Google Messages And Imessage Icons (Image credit: Joe Maring / Android Central)

When people choose a new messaging app for texting friends and family, they typically choose an actual app. So they'll weigh Telegram vs. Signal vs. WhatsApp, which give you reliable encryption, support for multiple devices, and other perks. But for your default texting app, you may not know the difference between RCS, SMS, and iMessage.

Your phone's built-in texting app may appear pretty basic on the surface. But there's more going on behind the scenes than you may initially think. And by having a stronger grasp of everything going on, you can be more confident about your messaging experience and understand why things do and don't work the way you'd expect.

Three main texting protocols exist in 2021, and today, we're talking about all of them. Let's get started!

RCS: The texting upgrade we've been waiting for

RCS settings in Google Messages

Source: Android Central (Image credit: Source: Android Central)

First on the list, we have RCS. You may already be using RCS on your Android phone right now and have no idea, and that's part of the reason why understanding the tech is so complicated.

RCS is short for "Rich Communication Suite," and it's essentially an upgraded version of the SMS texting standard we've had since the 1980s. RCS looks and functions a lot like the texting you've had for years, but it throws in a few extra features to make the whole experience that much better.

What kind of features are we talking about? Similar to the messaging experience you'd find in something like WhatsApp or Facebook Messenger, RCS allows your texting app to send messages over Wi-Fi, show read receipts when someone's seen your message, support high-resolution file/picture sharing, and more.

Getting RCS on your phone used to mean needing a specific handset and relying on your carrier to support the feature, but as of November 2020, RCS is globally available to anyone using the Google Messages texting app. So if you have an Android phone and want to learn how to enable RCS features, all you have to do is make sure you have Google Messages and then enable Chat features in the settings. That's it!

Pixel Google Messages Oops

Source: Jeramy Johnson / Android Central (Image credit: Source: Jeramy Johnson / Android Central)

RCS encryption doesn't prevent your carrier from reading your messages or holding onto your attachments. The Google Messages app does have reliable end-to-end encryption, adding a massive layer of security SMS just can't compete with. But other RCS-compliant apps will or won't support proper encryption on a case-by-case basis.

RCS is great, but it's far from replacing SMS any time soon.

RCS features will automatically kick in if you message someone who has it enabled on their end, but you get kicked back to regular SMS texting if they don't. Getting RCS set up on an Android phone is pretty simple for someone who hasn't done it yet, but extra work still needs to be done for that to happen.

There's also the fact that you need an Android phone. iPhones still don't support RCS in any manner, so if you have an Android phone with RCS and text someone with an iPhone, you'll always be right back to SMS. Considering that iPhones account for around 45% of all smartphones in the U.S., that's a big problem.

The whole pitch of RCS was that it was supposed to become the new universal standard that would replace SMS, but as we've seen over the years, that hasn't exactly happened. There's been a lot of positive progress made to make RCS more accessible to people who want to use it, but a full-on SMS replacement is not a title RCS has earned yet.

SMS: Holding strong as the universal standard

Google Mesages on a Pixel 3

Source: Joe Maring / Android Central (Image credit: Source: Joe Maring / Android Central)

Because of all that, SMS remains the default standard for text messaging. It works on Android and iOS and likely won't be going anywhere any time soon. That universal ease-of-use is the most significant advantage SMS texting still enjoys, but looking at it from any other angle, SMS is really showing its age.

SMS virtually has no added features outside of the basic texting experience, for starters. So you can't see when someone reads your message, and you need to rely on your cellular connection to send/receive messages. What's more, file sharing over SMS is limited to 3.5MB resulting in much lower-resolution images and videos.

An even bigger concern is SMS's inadequate security. SMS text messages can be easily intercepted if someone wants to access your messages badly enough, meaning you should think twice before sending private information to someone using it. Outside of possibly being intercepted by bad actors, there's also the fact that SMS messages are stored by carriers and can be used how they see fit. When messaging someone over RCS through the Google Messages app, you don't have to worry about these privacy concerns.

It's no secret that SMS is considerably less capable than RCS or iMessage, but the fact remains that its ubiquity is still unmatched. If you have someone's number, you can send them a text and know they'll receive it — there's no fussing with enabling certain settings or making sure you have the right app installed. Until RCS can address that, SMS will always have the upper hand in this regard.

iMessage: Apple's messaging giant

iMessage app icon on an iPhone XS

Source: Joe Maring / Android Central (Image credit: Source: Joe Maring / Android Central)

And, of course, we have iMessage — Apple's messaging service that's dominated iPhones since its release in 2011. iMessage is similar to RCS because it offers an enriched messaging experience compared to SMS, but unlike RCS, using iMessage is as simple as it could be.

If you have an iPhone and message someone else with an iPhone, you're talking to them over iMessage. This is immediately apparent by the blue chat bubbles you see in your iMessage conversations, and even better, you don't have to enable a setting or toggle for iMessage to work. If you message a non-iMessage number through the iPhone's Messages app, you'll use standard SMS texting, denoted by green chat bubbles instead of blue ones.

iMessage open on an iPhone X

Source: Daniel Bader / Android Central (Image credit: Source: Daniel Bader / Android Central)

Like RCS with Google Messages, iMessage conversations are secured with end-to-end encryption. Whether you're sharing the latest memes or having a serious chat with your friend, you can rest assured that no one — not even Apple or your carrier — is seeing your conversation. iMessage has its fair share of features to offer, too, including:

  • Messaging over Wi-Fi/data
  • Read receipts
  • Typing indicators
  • High-quality image sharing
  • Message reactions and replies
  • Message effects

The popularity of iMessage is impossible to ignore, but of course, it all comes with one major catch: iMessage isn't officially available for Android. Google Messages interpreted Apple emoji as text until late 2021, and other iMessage effects and tools don't work between iMessage and RCS.

Apple considered making iMessage available on Android, but chose not to because its exclusivity helps keep people on iOS. So it has no motivation to make its tools more compatible with other phones; instead, people with the "wrong" phones feel pressured to buy an iPhone to better communicate with family and friends.

There are third-party apps that allow you to get iMessage on an Android phone with a bit of tinkering and equipment, but it requires a lot more work than just downloading an app from the Play Store.

This makes iMessage more limited by design than SMS texting, but it was never created to replace SMS. Instead, it's more akin to something like Telegram or Signal, but because it's installed by default on iPhones and so widely used, it's often seen in the same light.

The current state of texting in 2021

RCS messaging

Source: Android Central (Image credit: Source: Android Central)

While this article is labeled as a versus comparison between RCS, SMS, and iMessage, declaring one the sole winner over the others doesn't really make sense. All three platforms have their fair share of pros and cons, and that's ultimately the main takeaway.

It's difficult to say if RCS will ever replace SMS completely, but there's a lot to like even in its current state. It has a generous feature-set, the addition of end-to-end encryption is a huge boon for security, and Google's Messages app has made it substantially easier to use RCS than it was a few short years ago.

RCS, SMS, and iMessage all have their place in 2021.

But so long as RCS isn't supported on iOS and accessing it on Android still requires work from the user, SMS will continue to be the fallback for non-RCS and iMessage conversations. It may lack features and security, but being able to send a message to a phone number and know it'll be delivered remains its pièce de résistance.

Finally, for those of you with an iPhone, iMessage will keep on trucking as the default messaging experience for the platform. Its lacking Android availability is a huge bummer. But even if that never changes, it's difficult to imagine a world where iMessage doesn't exist — it's just that good and that popular.

The messaging world in 2021 is a lot more complicated than we'd like, but that's the hand we've been dealt. Now, at least, you can go into it with a bit more confidence about everything going on.

Michael L Hicks
Michael L Hicks

Michael spent years freelancing on every tech topic under the sun before settling down on the real exciting stuff: virtual reality, fitness wearables, gaming, and how tech intersects with our world. He's a semi-reformed Apple-to-Android user who loves running, D&D, and Star Wars. Find him on Twitter at @Michael_L_Hicks.

22 Comments
  • RCS is hard to enable? Load or open Google Messages and agree or toggle on chat features? Samsung Messages seems to do this by default. The only thing keeping SMS going seems to be Apple and its lacking adoption of RCS for enabling their 14 percent or so of global users to have a similar experience when communicating with the other 86% of the worlds Android users. WhatsApp and FB Messenger exploaded as cross platform services globally prior to RCS adoption and push by Google and foot dragging carriers. Thankfully other good options like Signal and Telegram exist as well. BBM really blew things not going cross-platform earlier. If Apple's global smartphone sales were to slide not being cross-platform will be iMessages demise as well. The walled Apple garden has already left them and FaceTime out of global opportunities the past year in the business and personal space where Zoom and Microsoft Teams have thrived.
  • zoom is the video messaging app. apple lost with facetime
  • Apple hasn't adopted RCS for two reasons (IMHO). 1) it isn't a universally accepted and adopted standard, so would add little to their customers. iMessage could as easily revert to RCS vs SMS for mixed messaging, but that doesn't have the same universality as SMS today. 2) Security. RCS has no inherent security. The P2P encryption noted is a Google extension that is not part of the standard. Even that doesn't support encryption for group chats, which iMessage does, so it is less secure for Apple's users. Those are legitimate concerns, and there is also the benefit of keeping Apple users in the gated community.
  • RCS is available on a majority of phones in existence, so "AndroidCentral" makes it out to be the red-headed stepchild and is just "too hard" to set up. iMessage is available to a relatively small percentage of users in the world, but "AndroidCentral" extols upon it as if it is manna from Heaven. This is 💩.
  • Don’t knock iMessage til you’ve tried ti, it’s actually decent and the unfortunately the best messaging with it being limited to the iPhone is it’s only downfall for me, as you can actually send high quality video and pictures.
  • iMessage isn't cross platform so its dead on arrival. I don't want to have to think about what phone or platform the other person is using.
  • You can say that about RCS? I text a few Iphone users, so even if I had RCS enabled it would not make a difference. Granted there is more Android phone users than Iphones, but RCs is still not cross-platform.
  • Yes, RCS is cross-platform. Apple simply needs to implement it. There is nothing stopping them. iMessage is NOT as you can't use it outside of Apple. Apple will not allow it.
  • imessage is utterly useless since it only works on iphones
  • Texting is the basic mode of sending messages on a phone. It is simple. It is elegant. It is not for everyone. People with special needs have lots of alternatives. For my purposes txting is all I need. In the US unlimited txting is a part of virtually every plan available. It costs the same if I send 1 text or 10 thousand. Can't complain about that.
  • Just to be clear when I say txting I mean SMS and i dont also mean RCS. Don't need Fuzzylumpkin to come along and start splitting hairs. He enjoys it so.
  • Dude SMS is many things but elegant it is not. If you think this it just means you're to stubborn to see what is.
  • I would not call it elegant, but then again I would not call any messaging service elegant, but like jimmy hallmark, texting for me is all I need, it does the job of sending a message to someone, what else do I need? Also, like jimmy, I have unlimited text, so i can send how many I want.
  • I think you are absolutely right. I was amused by the subtitle, "It's time to understand texting." Texting uses text. Think MS Notepad. All the additional flowers, emojis, pictures, video, blah, blah is not text. The idea was Short Message Service, get some information from one place to another. Ruffles and flourishes are nice, but there are plenty of apps for that, many cross platform. There certainly are some improvements that can be made in 'texting', but they don't necessarily involve pictures videos and emojis. Read receipts would be nice. Standardized security, not just P2P, but group as well. If RCS implemented that and did take over as the replacement for SMS, most assuredly the green bubble in iMessage would mean you are using RCS vs SMS.
  • wait. Since the 1980's? Lol Yeah, ok. I bet you were not even alive then.
  • Outside of North America even iPhone users use WhatsApp.
  • But SMS uses your cell network while rcs and imessage and whatsapp all use internet (wifi or data) ? So big deal? Rcs is just like another "messenger app"? I mean there are hundreds of messaging apps out there.. Imessage is one that popular because it comes on the iPhone.. But what use rcs over whatsapp or anything else?
  • RCS was to be the next standard. That is until the carriers decided to D around. They all tried to carve their own slice of it. In so doing it's floundered badly. When Google tried to get everyone together they balked. It was soo bad that the US carriers formed their own group to thwart Google. Let me be clear here, I'm not giving Google a pass on this. There have been plenty of times they could have fixed this themselves but decided against it. Now we're stuck with this. A fractured messaging system with too many people trying to own it instead of making it work. Apple with iMessage is a problem here in that it is the dominant app for this in the US. I know not the world, but that's the issue here. Whatsapp for what it was was about as close to what Google needed. Then FaceBook decided to really screw the pooch and they've lost many to Signal and Telegram. Those though require more effort for them to work than most non tech (Friends and Family) want to put into. So here we are still stuck with the kludge that is SMS. Can this work? Yes, yes it can. To do that though will require all parties to be forced to work with each other. Neither side of the Bought Off Aisle is inclined to do just that.
  • i dont have a texting plan since I'm on vzw grandfathered unltd data, so i don't care about any and I use Google Voice, and everyone uses Facebook Messenger anyway. But this is AndroidCentral so no need to even mention imessage
  • Am I the only one who just uses text messages for simple communication? I really don't care if people read my messages or are in the process of replying. I often send messages and move on to something else and reply when I can. I don't need my messages going through Apple servers. I also see no value in saving text messages. Once the conversation ends, I just delete it.
  • I thought I heard about Apple turning over iMessage conversations to the FBI.
    If true, would that not mean the encryption means jack diddly?
  • meanwhile Google Voice still doesn't participate in RCS like it should. Google and others could take a few steps to help out the messaging situation, but they don't.