AssemblyAI
AssemblyAI / assemblyai.com
Developer speech recognition and audio intelligence API with transcription, speaker diarisation, sentiment analysis, topic detection, content safety, and LLM reasoning on audio via the LeMUR feature.
Pricing
Free
Free plan
Yes
Category
Audio
Platforms
5
Free plan
Yes
API access
Yes
Open source
No
Platforms
5
What is AssemblyAI?
AssemblyAI differentiates from pure transcription services by packaging speech recognition with a suite of audio intelligence features — sentiment analysis, entity detection, topic detection, content safety, and LeMUR for applying LLM reasoning directly to audio — in a single API call.
This all-in-one approach reduces the services needed for voice-enabled applications, podcast analysis, call centre analytics, and media processing. The Universal-2 model achieves strong accuracy across diverse audio conditions including phone calls. The generous $50 free credit drives strong developer adoption across podcast tools, interview processing, and meeting analytics applications.
How AssemblyAI works
AssemblyAI runs as speech-to-text software built around audio and text workflows. Users typically start with a prompt, upload, or connected data source, and the underlying model handles the heavy lifting before returning a result you can refine or export. It's available on web, python, and node.js, with API access for teams that want to embed it into their own products.
Watch AssemblyAI in action
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What makes it worth shortlisting
The capabilities that matter most for teams evaluating AssemblyAI.
LeMUR
Applies LLM reasoning to audio for Q&A, summarisation, and data extraction without manual transcript handling.
Audio intelligence
Sentiment analysis, entity detection, topic detection, and content safety applied to audio in the transcription pipeline.
Universal-2
High-accuracy model across diverse audio conditions including lower-quality phone and conference recordings.
Best use cases
Who should use it
Pros
- All-in-one transcription plus audio intelligence in single API calls
- LeMUR enables LLM reasoning on audio without manual transcript processing
- $50 free credit enables meaningful evaluation at no cost
- Universal-2 handles diverse audio quality including phone calls
Cons
- Intelligence features add latency vs pure transcription
- Real-time latency higher than Deepgram for voice AI
- Enterprise pricing requires sales engagement
Is it worth the price?
Free $50 credit for new accounts. Best model $0.37/hr. Nano $0.12/hr. Real-time streaming $0.30/hr. Enterprise custom pricing.
Model
Usage-based
Starting price
Free
Free trial
No
Tools like AssemblyAI
Deepgram is faster for real-time streaming. Rev.ai focuses on enterprise batch processing. Whisper provides free self-hosted transcription.
AssemblyAI vs Rev.ai
A side-by-side look at the closest alternative in this category.
AssemblyAI
AssemblyAI
Rev.ai
Rev.com
Free $50 credit for new accounts. Best model $0.37/hr. Nano $0.12/hr. Real-time streaming $0.30/hr. Enterprise custom pricing.
Free trial with 300 minutes of transcription. Usage-based at $0.02/minute for async transcription. $0.021/minute for streaming. Custom enterprise pricing.
SOC 2 Type II. GDPR compliant. HIPAA eligible with BAA. Data deleted after processing by default.
Enterprise includes HIPAA Business Associate Agreements. SOC 2 Type II certified. GDPR compliant.
Review AssemblyAI's data handling policy. Audio data processed on AssemblyAI's infrastructure and deleted by default after processing.
Review Rev.ai's data handling policy. Audio submitted for transcription is processed by Rev.ai's infrastructure. Enterprise includes BAA for HIPAA compliance.
- All-in-one transcription plus audio intelligence in single API calls
- LeMUR enables LLM reasoning on audio without manual transcript processing
- $50 free credit enables meaningful evaluation at no cost
- Universal-2 handles diverse audio quality including phone calls
- Strong transcription accuracy for English
- Reliable speaker diarisation for multi-speaker recordings
- Simple API integration with async and streaming support
- HIPAA-eligible for healthcare applications
- Intelligence features add latency vs pure transcription
- Real-time latency higher than Deepgram for voice AI
- Enterprise pricing requires sales engagement
- Developer-only product with no consumer interface
- Less suitable for consumer meeting note-taking use cases
- Multi-language coverage weaker than some competitors
- Custom model training requires Enterprise plan
Technical & deployment info
Key facts about model providers, platforms, and team support.
Model Provider
AssemblyAI
Models
Universal-2
Platforms
Web, Python, Node.js, Ruby, Go SDKs
Deployment
SaaS, API
Integrations
Python, Node.js, Go, Ruby, REST API, Webhooks
Team Collaboration
No
Launch Year
2017
Security & privacy
Compliance signals and data-handling notes as reported by the vendor.
SOC 2 Type II. GDPR compliant. HIPAA eligible with BAA. Data deleted after processing by default.
Review AssemblyAI's data handling policy. Audio data processed on AssemblyAI's infrastructure and deleted by default after processing.
What users are saying
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Common questions about AssemblyAI
Editorial Verdict
Should you use AssemblyAI?
AssemblyAI is the best choice for developers wanting transcription plus audio intelligence in a single API. For pure low-latency real-time transcription, Deepgram is faster.
Last verified July 24, 2026.