What is the difference between iMessage, RCS and SMS/MMS?
You can use the Messages app on your iPhone, iPad, Mac, Apple Watch or Apple Vision Pro to send messages. Those messages are sent as iMessage, RCS or SMS/MMS. Find out more about the difference between the message types.
iMessage
With iMessage, messages can be sent to another iPhone or another Apple device over Wi-Fi or mobile data networks. You can send texts, high-resolution photos and videos, documents, links, Tapbacks, text effects, Live Stickers, message effects and more. iMessage supports delivery and read receipts and typing indicators. Messages sent with iMessage will appear in blue text bubbles on your device.
When you use iMessage, your conversations are encrypted end-to-end, so they can’t be read while they’re sent between devices. Messages sent with iMessage will display a lock icon at the top to represent this.
Turn iMessage on or off in the Settings app. Tap Apps, then tap Messages.
If Wi-Fi is unavailable, messages sent with iMessage will be sent over mobile data. Cellular data rates may apply.
RCS
If you’re not using iMessage, you can use RCS. RCS text messages can be sent to non-Apple devices as well as another iPhone or another Apple device with Text Message Forwarding turned on. With RCS, you can send texts, high-resolution photos and videos, links, and more. RCS also supports delivery and read receipts and typing indicators. RCS messages appear in green text bubbles on your device.
Apple’s implementation of RCS is based on the industry standard. Starting with iOS 26.5, end-to-end encrypted RCS messaging (Beta) in Messages is available with supported service providers and will roll out over time. RCS messages can be end-to-end encrypted when all participants have service providers that support encryption.
Even if your service provider supports encrypted RCS messages, the encryption of each RCS conversation depends on whether your contact’s service provider also supports it. When end-to-end encrypted, RCS message conversations show “Encrypted” with a lock icon at the top. If you can’t see the indicator, your RCS messages aren’t protected from a third party reading them while they’re sent between devices.
RCS is a service provided by your service provider. When your device connects to your mobile network, it communicates with your service provider and their partners to set up RCS. User identifiers are exchanged for your service provider and their partners to authenticate your device and provide a connection. These identifiers include your phone number and, depending on your service provider, your current IP address.
To use RCS, you’ll need iOS 18 and a text-messaging plan from a service provider that supports RCS on iPhone. For end-to-end encryption in RCS message conversations, you’ll need iOS 26.5 and a service provider that supports end-to-end encryption. Contact your mobile service provider for more information.
Find out how to turn on RCS messaging
Find out whether your service provider supports RCS messaging (including end-to-end encryption)
There may be a delay of a few hours in activating RCS.
SMS/MMS
If you’re not using iMessage or RCS, you can use SMS/MMS. SMS and MMS messages can be sent to non-Apple devices as well as another iPhone or another Apple device with Text Message Forwarding turned on. With SMS/MMS, you can send texts, photos and videos, links and more. SMS/MMS messages appear in green text bubbles on your device.
SMS/MMS messages aren’t end-to-end encrypted, which means they’re not protected from a third party reading them while they’re sent between devices.
SMS and MMS are services provided by your service provider. When your device connects to your mobile network, it communicates with your service provider. User identifiers are exchanged for your service provider to authenticate your device. These identifiers could include but are not limited to your IMEI, IMSI, current IP address and phone number.
To use SMS/MMS on an iPhone, you’ll need a text-messaging plan that supports these services. Contact your wireless service provider for more information.
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