Speech to text vs text to speech: what is the difference?

Search for "tts" and you will find two completely different technologies sharing one acronym's worth of confusion. Speech to text and text to speech are mirror images of each other: one turns talking into writing, the other turns writing into talking. The names describe the direction of travel, and getting the direction right saves you from downloading the wrong category of tool entirely.

One turns talking into writing, the other turns writing into talking.

Text to speech: the computer reads to you

Text to speech (TTS) takes written words and speaks them aloud. You already hear it constantly: GPS navigation voices, screen readers like VoiceOver and NVDA, the "read aloud" button in your browser or ebook app, automated phone menus, and AI-narrated audiobooks. The input is text, the output is audio.

You want a TTS tool when listening is easier than reading: proofreading by ear, consuming articles while driving, or making content accessible to people who cannot comfortably read a screen. Most operating systems and browsers have a decent one built in, so for casual use you may not need to install anything at all.

Speech to text: you talk, the computer writes

Speech to text (STT), also called dictation or speech recognition, goes the other way. The input is your voice, the output is written words. This is what powers voice typing in Google Docs, voicemail transcriptions, meeting notes tools, and the microphone icon on your phone's keyboard. It is also what powers subtitling and podcast transcripts.

You want an STT tool when writing is the bottleneck: drafting emails faster than you can type, capturing thoughts hands-free, transcribing interviews or lectures, or working around an injury or condition that makes typing painful. Speaking is three to four times faster than average typing, which is why dictation keeps converts once the habit forms.

speaking

150 wpm

average conversational pace

typing

40 wpm

average sustained speed

first drafts

3–4×

faster spoken than typed

Why the mix-up matters

The two markets barely overlap, but the search terms do. Someone looking for a dictation tool who searches "tts" lands on narration software; someone wanting their documents read aloud who searches "speech to text" lands on transcription services. Thirty seconds spent on the direction of travel (voice in, or voice out?) gets you to the right aisle.

There is one place the two genuinely meet: accessibility. Many people use both directions daily, dictating their own messages with STT and having replies read back with TTS. They are complementary halves of a hands-free workflow, not competitors.

Where tautau fits

tautau is firmly on the speech-to-text side. The Chrome extension puts a mic button next to every text field on the web, so you can dictate emails, comments, and documents instead of typing them. If the audio already exists, tautau.xyz/transcribe turns YouTube videos, podcast episodes, and audio file links into text you can search, edit, and download. It will not read anything aloud to you; for that, your operating system's built-in narrator is genuinely good and already installed.

If dictation is the direction you need, install tautau from the Chrome Web Store and click into the next text field that would have been a chore to type. A free account gets you five dictations a day, no credit card required.