Speech-to-Text
The industry's best products need the industry's best models. Build on speech-to-text models that lead the way in accuracy and quality, accessible through a simple API.
Speech-to-text quality that speaks for itself.
Our Universal model sets the standard for accuracy and performance on the details that define speech-to-text quality.
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Saudi Arabia, Fiji, Tonga, Hong Kong and Bahrain. All these countries are using Austrian medical coding. For example, if you want to go to New Zealand, if you know Austrian medical coding, you can go New Zealand easily as a medical coder or clinical coder. So for example, if you want to go Singapore, but in Singapore they will use both ICD10CM and CPT and as well as Austrian medical coding. So now we can see how can I search job in Australia.
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Powering the world’s most trusted Voice AI products
Your product experience is only as good as the foundation that powers it. Make sure you build on the best.
The accuracy and quality that Voice AI apps require
Our speech-to-text models redefine what quality means for Voice AI by delivering transcripts that are consistently trustworthy, and built for real-world performance.
Capture meaning, not just sound with contextual prompting across every conversation- 57% better recognition of key terms like names, codes, and medical terms
- 64% reduction in speaker counting errors compared to competitors
- 1,000-word context-aware key term prompting for domain expertise compared to other leading speech-to-text models
Don't just transcribe speech, understand it
Analyze dialog flow and speaker relationships to capture who is speaking, what they mean, and why it matters.
- Track dialogue and speaker context across turns for natural comprehension
- Resolve ambiguity automatically — distinguishing between similar terms and acronyms
- Capture tone, corrections, and implied meaning to preserve intent
- Ensure reliable performance in overlapping, multi-speaker, and noisy environments
Reliable performance across the globe
We speak your customers' language, so you can serve a global customer base.
- 99-language support with automatic detection and code-switching between English and other languages
- Adapt to regional accents, dialects, and cultural expressions
- Language aware formatting for global date, number, and punctuation standards
- Handle medical, legal, and technical terms easily with specialized vocab
A single platform for all things Voice AI
Innovate, ship, and scale faster than ever, all on a developer-first API.
- Unified speech-to-intelligence pipeline through LLM Gateway
- Seamlessly integrate with leading LLMs, including OpenAI, Anthropic, and Google
- Reliable, enterprise-grade infrastructure with zero rate limits
- No contract, usage-based pricing that's built to scale with you
Capturing speech is where it starts. Creating outcomes is where it counts.
Learn why today’s most innovative companies choose us.
Reduction in customer complaints and support tickets
Conversion rate for their Conversational Intelligence product
Jiminny scored 15% higher customer win rates after implementing AssemblyAI.
Assembly is instrumental in our transcription process, providing crucial input for our LLM API to process further. It's become an integral part of our workflow.
Designed for voice experiences that feel more intuitive and responsive
International Language Support
Gain support to transcribe over 99+ languages and counting, including Global English (English and all of its accents).
Speaker Diarization
Detect multiple speakers in an audio file and what each speaker said. Receive a list of utterances, where each utterance corresponds to an uninterrupted segment of speech from a single speaker.
Automatic Language Detection
Identify the dominant language spoken in an audio file and use it during the transcription.
Word Timings
Receive a response that also includes an array with information about each word, and the start and end timings.
Auto Punctuation and Casing
Automatically add casing and punctuation of proper nouns to the transcription text.
Fewer correction loops and smoother conversations
Model | Overall | Alphanumerics | Proper Nouns |
|---|---|---|---|
AssemblyAI Universal | 93.32% | 4.00% | 13.87% |
Deepgram Nova-2 | 90.76% | 4.97% | 21.14% |
AssemblyAI's accuracy is better than any other tools in the market (and we have tried them all).
Frequently Asked Questions
A speech-to-text API is a developer interface that turns audio into text. Your app sends an audio file or live stream to an endpoint and receives a transcript, often with word timestamps, speaker labels, and confidence scores. Many providers support both batch and real-time transcription for integrating captions, notes, or analytics into products.
AssemblyAI’s Universal model leads our published benchmarks with a 93.3% Word Accuracy Rate and delivers near‑human accuracy, even on noisy or challenging audio.
Yes. For pre-recorded audio, AssemblyAI detects and transcribes code-switching, with best results for English+Spanish or English+German. Configure via language_codes (max two; one must be “en”) or enable language_detection with code_switching and an optional confidence threshold.
Yes. AssemblyAI offers real-time Streaming Speech-to-Text via a secure WebSocket API, returning partial and final transcripts within a few hundred milliseconds. It’s optimized for ultra-low latency (~300 ms P50) and supports use cases like live captioning and voice agents.
Sign up and get your API key in the Dashboard. Install an SDK (e.g., JavaScript). Initialize the client with your key, then call transcribe with your audio. For streaming/voice agents, set ASSEMBLYAI_API_KEY in your environment. Create keys in the Dashboard’s API Keys section.
Pay‑as‑you‑go: $0.15/hr for Universal (pre‑recorded and streaming); $0.27/hr for Slam‑1 (pre‑recorded). Billed per second. Optional Speech Understanding features are priced separately (e.g., Speaker Identification $0.02/hr).
Yes. AssemblyAI integrates with LLMs via LLM Gateway—a single API to OpenAI (GPT), Anthropic (Claude), Google (Gemini), and more. You can route transcripts directly to these models, switch providers without code changes, and use chat completions, multi-turn, tool calling, and agentic workflows, with unified management and billing.
Turn voice data into unparalleled product experiences
Partner with the leader in Speech AI to build powerful products with breakthrough industry impact.
