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. Learn 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 cellular-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 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 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 cellular data. Cellular data rates might apply.
RCS
If you aren’t 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 carriers and will roll out over time. RCS messages can be end-to-end encrypted when all participants have carriers that support encryption.
Even if your carrier supports encrypted RCS messages, the encryption of each RCS conversation depends on whether your contact's carrier also supports it. When end-to-end encrypted, RCS message conversations show "Encrypted" with a lock icon at the top. If you don'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 carrier-provided service. When your device connects to your cellular network, it communicates with your carrier and their partners to set up RCS. User identifiers are exchanged for your carrier and their partners to authenticate your device and provide a connection. These identifiers include your phone number and, depending on your carrier, your current IP address.
To use RCS, you need iOS 18 and a text-messaging plan from a carrier that supports RCS on iPhone. For end-to-end encryption in RCS message conversations, you need iOS 26.5 and a carrier that supports end-to-end encryption. Contact your wireless carrier for more information.
Learn how to turn on RCS messaging
Learn whether your carrier supports RCS messaging (including end-to-end encryption)
There may be a delay of a few hours in activating RCS.
SMS/MMS
If you aren’t 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 carrier-provided services. When your device connects to your cellular network, it communicates with your carrier. User identifiers are exchanged for your carrier 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 need a text-messaging plan that supports these services. Contact your wireless carrier for more information.
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