Real-Time Text (RTT) calls are transforming the way people connect, especially those who can’t use voice for calls. RTT lets users type and view text instantly during a phone call, letter by letter, without pressing “send.” It removes delays and supports natural, live conversations.
This feature is especially valuable for people who are deaf or hard of hearing, users with speech disabilities, caregivers, and anyone supporting accessible communication. It's also useful for seniors, emergency responders, and everyday smartphone users who may need a non-verbal way to make a call. In this article, you’ll learn what RTT is, how it works, who it helps, and how to use it on both Android and iPhone.
What Is an RTT Call?
RTT stands for Real-Time Text. It allows you to send and receive messages during a phone call, but unlike texting or chat apps, each letter appears on the screen as it’s typed—there’s no need to hit “send.”
Unlike SMS or even modern messaging apps, RTT is designed for live conversation. The other person sees what you’re typing as you type it. This means faster, clearer communication and less confusion, especially during critical or time-sensitive moments.
RTT works alongside phone calls, not instead of them. You’re technically on a call, but all the communication happens through text in real time. You can even combine it with voice if you want, depending on your phone settings.
This is especially useful in situations where fast feedback matters—like emergency calls or technical support—or where speech isn’t possible.
RTT vs. TTY: What’s the Difference?
TTY, or teletypewriter, has been around for decades. It was one of the first tools designed to help deaf or speech-impaired users communicate over phone lines. But it has limits.
With TTY, messages are typed, then sent one at a time. You can’t see what someone is writing until they’re done. RTT changes that by showing the message character by character, live. This feels more like a true conversation than a turn-based system.
TTY also requires special hardware. You’d need a TTY machine connected to a phone line. RTT doesn’t. It works on smartphones using software and your normal number.
Because of these improvements, many mobile carriers have started to phase out TTY support in favor of RTT. It’s more flexible, easier to use, and better for modern devices.
RTT is also better for mixed communication—some users might type while others talk. That blend isn’t possible with old TTY systems, which are strictly text-based.
How Does RTT Work on a Phone?
RTT uses your phone’s standard calling feature but replaces voice with a text interface. When you place a call using RTT, a text window appears instead of a dial pad or audio screen.
As you type, each character shows up in real time on the other person’s screen. You don’t need to press “Send.” It’s instant. This is helpful for fast replies or when spelling out information slowly.
The person on the other end can also respond in real time. That makes the flow of conversation feel much more natural than using traditional text messages or TTY.
Some phones also let you switch between text and voice. That means one person can speak while the other types—a helpful option when communication styles or abilities differ.
Who Can Benefit from RTT Calling?
RTT is designed to help anyone who can’t—or prefers not to—use voice calls. It improves accessibility for several user groups:
- People who are deaf
- People with speech disabilities
- Elderly users with voice limitations
- Emergency access users who can't talk during a call
RTT also works well in loud environments or quiet spaces where voice communication isn’t possible.
How to Enable RTT on iPhone and Android
Enabling RTT is simple and only takes a few taps in your phone’s settings. Some carriers may require Wi-Fi calling to be turned on for RTT to function properly.
On Android:
- Open the Phone app
- Tap Settings
- Go to Accessibility
- Tap RTT settings and turn it on
On iPhone:
- Go to Settings
- Tap Accessibility
- Select RTT/TTY
- Turn on RTT and configure as needed
Once enabled, you’ll see the option to start RTT during or before a call.
Where RTT Works and Carrier Support
RTT is supported by most major U.S. carriers, including Verizon, AT&T, and T-Mobile. The feature is available on many modern Android and iOS devices, especially when Wi-Fi calling is turned on.
In the United States, the FCC requires RTT support for emergency calls like 911. This ensures that users who rely on RTT can still reach help even if they can’t speak during the call.
Final Thoughts: Is RTT Right for You or Someone You Know?
RTT is more than just a texting tool. It’s a real-time bridge for communication that helps users stay connected without voice. Whether you need it daily or only during emergencies, it’s a feature worth enabling and understanding.
If you or someone you know could benefit from RTT, try turning it on. It could make phone communication easier, faster, and more inclusive for everyone.