What Is RTT on an iPhone, and How Do I Use It?

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When you type out a message and tap “Send,” it feels like it’s sent instantly. However, there’s an even faster method called “RTT”, and it’s a valuable feature for the hearing and speech impaired.

What Is RTT?

“RTT” stands for “Real-Time Text,” and it’s a protocol for text calls. That’s right, it’s not text messaging as you might normally think. RTT is a way to have a text conversation in real time over a phone call.

But isn’t regular text messaging in real-time? Somewhat. With regular text messaging, you type out a full message and send it when you’re ready. However, in an RTT conversation, you or the person on the other end can see what’s being typed as it’s being typed.

You’ll find RTT in the iPhone’s “Accessibility” menu, and that’s the true value of this feature. Phone calls can be difficult for the hearing and speech impaired, but texting and instant messaging apps lack the feel of a “face-to-face” conversation. RTT attempts to bridge that gap.

It should be noted that you do have the option to use RTT in a more standard text messaging fashion—sending full messages—but the real-time aspect is what makes the protocol interesting. Either person on the call (or both) can use RTT.

Related: How to Use Live Captions on an iPhone

How to Enable RTT on iPhone

First, open the “Settings” app on your iPhone.

Open the Settings.

We’re going to go to the “Accessibility” section.


Scroll down and select “RTT/TTY.”


The first thing to do is toggle on “Software RTT/TTY” at the top. Tap “Allow” when it asks for permission to send notifications.


Next, we’ll need to fill in the “Relay Number.” In the U.S., the number is “711”, and it’s probably already filled in.

Enter the

Under the Relay Number is the “Send Immediately” toggle. Turn this off if you don’t want your texting to appear in real time.

There are two other toggles you may want to use. “Answer RTT Calls as Muted” will turn off your microphone in an RTT call. “Answer All Calls as RTT/TTY” will prevent you from having to turn it on every time.

More RTT options to choose from.

How to Use RTT in a Phone Call

To get started with RTT in a phone call, we’ll first start a call just like you normally would. You will see “RTT/TTY Call” and “RTT/TTY Relay Call,” either one will work.

Start a call and select

After the call has been connected, tap the “RTT” button in the dialer.

Tap the

This will bring up the keyboard and the conversation view. Type your message and watch it appear in real time. You’ll need to tap the send button if you turned off “Send Immediately.”

The RTT conversation.

That’s the basics of RTT on the iPhone. It’s a pretty cool accessibility feature for those who may have trouble hearing or speaking in phone calls. It can also be used as a way to have hyper-instant messaging conversations. Now you know!

Related: Make Your iPhone Easier to Use With These Hidden Accessibility Features

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