The best way to build Voice AI apps

Today’s top Voice AI companies rely on AssemblyAI’s speech-to-text and speech understanding models to launch groundbreaking products fast and scale with ease.

Streaming Speech-to-Text

Try stating information like names, dates, and address, along with technical data like codes, commands, formulas, and special formatting to see how our model performs...

Universal-3 Pro Streaming

Context-aware

Audio tags

Verbatim

Keyterms

Speaker roles

Code switching

Clinical evaluation history:

Without prompting

"I just want to move you along a bit further. Do you take any prescribed medicines? I know you've got diabetes and high blood pressure. I do. I take Ramipril. Okay. And I take Metformin, and there's another one that begins with G for the diabetes. Glicoside."

With context aware prompting

"I just wanna move you along a bit further. Do you take any prescribed medicines? I know you've got diabetes and high blood pressure. I, I do. I take, um, I take Ramipril. Okay, mhm. And I take Metformin, and there's another one that begins with G for the diabetes. So glycosi — glycosi— glycoside."

Non-speech audio event:

Without audio tagging

"Your call has been forwarded to an automatic voice message system. At the tone, please record your message. When you have finished recording, you may hang up or press 1 for more options."

With audio tagging

"Your call has been forwarded to an automatic voice message system. At the tone, please record your message. When you have finished recording, you may hang up or press 1 for more options. [beep]"

Speech with disfluencies:

Without disfluency prompting

"Do you and Quentin still socialize when you come to Los Angeles, or is it like he's so used to having you here? No, no, no, we're friends. What do you do with him?"

With disfluency prompting

"Do you and Quentin still socialize, uh, when you come to Los Angeles, or is it like he's so used to having you here? No, no, no, we, we, we're friends. What do you do with him?"

Proper noun spelling:

Without keyterms prompting

"Hi, this is Kelly Byrne Donahue."

With keyterms prompting

"Hi, this is Kelly Byrne-Donahue."

Capturing speaker roles:

With traditional speaker labels

Speaker A: 5Mg. And do you take it regularly?

Speaker B: Oh yeah, yeah.

Speaker A: Good.

Speaker B: Every evening.

With speaker labels prompting

Speaker [Nurse]: 5Mg. And do you take it regularly?

Speaker [Patient]: Oh yeah, yeah.

Speaker [Nurse]: Good.

Speaker [Patient]: Every evening.

Spanish and english audio:

Without codeswitching

"Would definitely think I spoke Spanish if you heard me speak Spanish. But I still make mistakes. Soy wines. Paltro Soy. La fundadora de goop. Thank you. Thank you for doing that."

With codeswitching

"You would definitely think I spoke Spanish if you heard me speak Spanish, but I still make mistakes. Soy Gwyneth Paltrow, soy la fundadora de Goop. Thank you. Thank you for doing that."

The industry’s best products need the industry’s best models

We build the most accurate, fully featured models on the market, so you can ship with confidence knowing that you’re building on the best.

Avoid garbage in, garbage out

Your product experience is only as good as the inputs it’s built on. AssemblyAI’s models lead the industry in accuracy and reliability.

  • Industry’s lowest Word Error Rate (WER)
  • Up to 30% less hallucinations than other providers
  • Preferred by 73% of end users in unbiased evaluations

Go beyond transcription

Access a full suite of speech understanding capabilities to uncover insights, identify speakers, and build powerful product experiences.

  • Correctly identify speakers with advanced diarization capabilities
  • Automatically format text and alphanumerics for clearer outputs
  • Accurately capture multilingual speech with automatic language detection

Easy to start, even easier to scale

We built AssemblyAI to be the easiest platform on the market for developers to build, ship, and scale on.

  • Serving 600M+ inference calls and over 840M API calls per month
  • Over 40 terabytes of audio processed daily
  • Pay only for what you use and scale to millions of hours without contracts or throttles

We’re not playing around—but you can

Put our AI models to the test in our no-code playground.

Unlock the value of voice data

Build what’s next on the platform powering thousands of the industry’s leading voice AI apps.