Glossary
Real-time text (RTT)
Real-time text (RTT) is a way of sending text as it is typed, so the other person can read each word before the sender finishes. It is used in conversation by many deaf and hard of hearing people, and it has no send step like an ordinary text message. It is a typing channel, not a speech technology.
Updated October 17, 20262 cited facts, each traced to its source
Also called RTT.
Real-time text (RTT) is a way of sending text as it is typed. Each character reaches the other person while you type it, instead of arriving as a finished message after you press send. The reader sees the message form in front of them. Wikipedia describes the core idea directly: real-time text allows the other person to read immediately, without waiting for the sender to finish composing their sentence or message 1.
RTT is a typing technology. It does not turn speech into text, so it is not dictation and it is not captioning. The words are typed by a person, and the other person reads them as they arrive.
How a conversation works in RTT
In an ordinary text message, you write the whole message, press send, and the other person sees it all at once. In RTT, the other person sees your words as you type them, the way a listener hears a speaker in real time. That is why RTT suits conversation. A reply can start before the first message is finished, and the two people can interrupt each other in writing.
Who uses it
Real-time text is used heavily by deaf and hard of hearing people. It appears in telecommunications relay services, in TTY and TDD devices, and in Text over IP, according to the same Wikipedia summary. It is also used in some instant messaging software and in live captioning systems.
Example: a phone call handled in text
A person who is deaf calls a clinic on a phone with RTT turned on. They type the reason for the call, and the receptionist reads each word as it appears and replies in text. Neither person waits for a full message, so the call moves at the speed of typing.
Why it matters for dictation and typing
RTT and dictation solve different problems. Dictation saves you from typing by letting you speak. RTT lets people who type communicate in real time, which matters for people who cannot hear a phone call or who cannot speak clearly on it. A reader who depends on text, rather than sound, can do much better with a channel that shows words as they form.
Accuracy and speed still matter. A study of captioning found that even with accurate real-time text from human captioners, deaf and hard of hearing people received 50 to 80 percent of the information, against 84 to 95 percent for hearing peers 2. The gap shows that real-time text helps but does not restore the full conversation. Plan for repetition and for shared context when you rely on it.
For the captioning side of the same problem, see Live Captions and Live Transcribe, which turn speech around you into text. For a closely related term, see CART captioning, where a trained captioner types speech in real time.
Related terms
- Live Captions: on-screen captions for speech and audio, produced by the phone.
- Live Transcribe: Google's Android app for captioning a conversation.
- Assistive technology: tools that help people with a disability communicate and use devices.
- Dictation: speaking so that your own words are written into a text field.
Guides that cover it
- Speech to text for deaf and hard of hearing people: how speech to text and captions fit into daily communication.
- Dictation on phones and tablets: our overview of speaking to text on iPhone, iPad and Android.
Evidence
Every number on this page, with where it comes from. Open a fact to see the exact words in its source.
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- 2.
Related terms
- Dictation and Voice to Text on iPhone and AndroidThe topic this term belongs to
- Allow Full AccessAllow Full Access is an iPhone setting that you switch on for a third-party keyboard before it can have open access, such as network access. Apple warns that a keyboard with this setting on is permitted to collect and transmit the text you type.
- GboardGboard is Google's keyboard app for Android and iPhone, and its microphone key turns speech into text in any app where you can type. On Android it can run speech recognition on the phone, while on iPhone the voice input is handled inside the Gboard app and sent to Google.
- Google voice typingGoogle voice typing is the speech-to-text input that Google provides on Android, so you can speak words into a text field. Its name and location vary by phone: Gboard shows a microphone key, while Samsung Galaxy phones list Google Voice Typing next to their own voice input.
- Live CaptionsLive Captions is a feature that shows text for speech and audio as it happens, using the phone's own processing. Google calls it Live Caption on Pixel phones, and Apple calls it Live Captions on iPhone. It reads what others say, so it is the reverse of dictation.
- Live TranscribeLive Transcribe is a Google app for Android phones that turns the speech of people around you into captions as they talk. It helps you follow a conversation. It does not type your own words into a text field, which is what dictation does.
- Samsung voice inputSamsung voice input is the voice-to-text feature built into the Samsung Keyboard on Galaxy phones and tablets. It works only with that keyboard, so it is a separate choice from Google Voice Typing.
- Speech Services by GoogleSpeech Services by Google is the Android speech engine from Google that turns speech into text for other apps and reads on-screen text aloud. Google's Play Store listing now uses the title Speech Recognition & Synthesis, and reviews on that listing still call the app by the older name.
- Third-party keyboardA third-party keyboard is a keyboard app from a developer other than the phone's maker, which you install and switch to in place of the built-in keyboard. Apple calls the iPhone version a custom keyboard, and Apple's rules limit what it can do, such as network access and microphone use.
- Transcript Assist (Galaxy AI)Transcript Assist is a Samsung Galaxy AI feature that converts a saved recording in the Voice Recorder app into text. It works on select Galaxy models and needs a working internet connection. It transcribes recordings you already made, so it is not live dictation into a text field.
- Voice Access (Android)Voice Access (Android) is a Google feature that lets you operate an Android phone or tablet by speaking commands, such as opening an app or tapping a labelled item. Google built it for people who have difficulty using a touch screen. It is a control tool that can also enter text, and it is separate from Windows Voice Access on PCs.
- Voice message transcriptsA voice message transcript is written text of the words in an audio message, produced by the messaging app so you can read instead of listen. Apple, Google and WhatsApp each offer one, with different defaults and different privacy arrangements. It turns audio into text, the reverse of dictation.