What is AssemblyAI?

AssemblyAI AssemblyAI delivers real‑time and batch speech‑to‑text transcription with high accuracy and low latency, supporting more than 99 languages and code‑switching scenarios. The platform includes advanced speech‑understanding features such as speaker diarization, sentiment analysis, chapter detection, and automatic language identification.

Custom prompts enable granular control of disfluencies, fillers, and speaker roles for conversational analysis. Medical Mode provides terminology‑specific accuracy for clinical transcripts, while PII redaction tools remove personal identifiers automatically.

Developers can integrate the API via simple REST calls or SDKs, scale to millions of inference requests, and deploy on cloud or self‑hosted environments for compliance. AssemblyAI’s models excel in word‑error‑rate reduction and hallucination suppression, making them suitable for call centers, voice assistants, and content summarization workflows.

AssemblyAI on the web:

AssemblyAI details

Company: AssemblyAI Inc.
Jurisdiction: State of Delaware
Built for: Developers
Stated compliance: HIPAA

Compliance as stated in AssemblyAI's own published documentation.

AssemblyAI tech specs

Works with: OpenAI / Whisper Anthropic / Claude Google / Gemini

AssemblyAI pricing

Freemium

Key phrases $0.01

Profanity filtering $0.01

Sentiment analysis $0.02

Custom formatting $0.03

Summarization $0.03

Keyterms prompting add-on $0.04

Pii audio redaction $0.05

Gpt-5 nano $0.05

Translation $0.06

Gpt-oss-20b $0.07

Entity detection $0.08

Auto chapters $0.08

Pii redaction $0.08

Gemini 2.5 flash lite $0.10

Speaker diarization add-on $0.12

Start building as low as $0.15/hr $0.15

Universal-2 $0.15

Universal-streaming $0.15

Universal-streaming multilingual $0.15

Topic detection $0.15

Content moderation $0.15

Gpt-oss-120b $0.15

Qwen3 next 80b a3b $0.15

Qwen3 32b $0.15

Universal-3 pro $0.21

Gpt-5-mini $0.25

Claude 3 haiku $0.25

Whisper-streaming $0.30

Gemini 2.5 flash $0.30

Gemini 3 flash $0.50

Kimi k2.5 $0.60

Claude 3.5 haiku $0.80

Claude 4.5 haiku $1.00

Gpt-5.1 $1.25

Gpt-5 $1.25

Gemini 2.5 pro $1.25

Gpt-5.2 $1.75

Gpt 4.1 $2.00

Gemini 3 pro $2.00

Claude 4.6 sonnet $3.00

Claude 4.5 sonnet $3.00

Claude 4 sonnet $3.00

Chatgpt-4o $5.00

Claude 4.6 opus $5.00

Claude 4.5 opus $5.00

Claude 4 opus $15.00

Pay as you go varies

Speech understanding varies

Verify on the official pricing page.

View plans

AssemblyAI's key features

Real-time streaming transcription
1500-word contextual prompting
Speaker diarization and labeling
Automatic language detection code-switching
Auto punctuation and casing
Multilingual support 99+ languages
LLM gateway integration

AssemblyAI use cases

Stream real‑time customer support calls into AssemblyAI, automatically transcribing and sentiment‑analyzing the conversation, then highlighting key issues and providing speaker diarization for accurate agent performance reviews.
Convert entire hours of medical dictations into structured text with AssemblyAI’s medical terminology model, simultaneously redacting all PII and extracting key clinical entities for seamless EHR integration.
Transcribe multilingual podcast episodes in batch, using AssemblyAI’s language detection and speaker diarization to generate separate subtitle files per speaker and per language, then publish them with accurate captions and SEO metadata.

AssemblyAI user reviews

Based on 9 reviews, 44% of users recommend AssemblyAI, rated highly for ease of use.

recommend

don't

9 reviews

Liked for

Worth the price 4 of 4

Easy to use 4 of 4

Good integrations 4 of 4

Quality results 2 of 4

All key features 1 of 4

Disliked for

Missing features 3 of 5

Inconsistent results 2 of 5

Not worth the price 1 of 5

Hard to use 1 of 5

Lacks integrations 1 of 5

Would you recommend AssemblyAI?

Recommend this tool?

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Who is AssemblyAI for?

Software developers
Technology startups
Large enterprises
Technical architects
Innovation leaders

AssemblyAI FAQ

Is AssemblyAI free?

Partly. AssemblyAI has a free plan with usage limits, and paid plans unlock the full feature set. Plans include Key phrases at $0.01, Profanity filtering at $0.01, Sentiment analysis at $0.02 and Custom formatting at $0.03.

Is AssemblyAI safe to use?

AssemblyAI states HIPAA compliance in its own published documentation. AssemblyAI is operated by AssemblyAI Inc., registered in State of Delaware. AssemblyAI carries the TopAI.tools verified mark, which we award after a manual review of pricing transparency, published terms, public following and working functionality.

What are the best alternatives to AssemblyAI?

The closest alternatives to AssemblyAI are Deepgram Voice AI, Whisper AI, Speech-to-Speech, TurboScribe and AccurateScribe.ai. You can compare them side by side in the alternatives section further down this page.

What does AssemblyAI do with my data?

AssemblyAI states that customer content may be used to train its models. Its privacy policy states that personal data is sold or shared for marketing purposes. Data may be shared with third-party service providers that help run the product.

Does AssemblyAI have an API?

Yes. AssemblyAI offers an API, so you can call it from your own applications instead of using the interface directly.

Who made AssemblyAI?

AssemblyAI is built and operated by AssemblyAI Inc., a company registered in State of Delaware.

Which AI models does AssemblyAI use?

AssemblyAI is built on OpenAI / Whisper, Anthropic / Claude and Google / Gemini. Which models you can reach may depend on your plan.

Compliance, privacy and billing terms are as stated in each product's own published documentation and have not been independently verified by TopAI.tools.