Overview of AssemblyAI Speech Recognition API: Accurate Speech-to-Text Transcription and Audio Analysis
AssemblyAI offers industry-leading speech recognition AI models to transcribe audio to text and analyze speech data.
Key features:
- Accurate speech-to-text transcription for audio files, video files, live speech and more
- Speaker detection, sentiment analysis, chapter detection
- PII redaction, speech summarization and more
- Easy integration with Python, Node.js, Java and REST APIs
- Competitive pricing that scales as you grow
- 24/7 customer support from AI experts
How AssemblyAI Speech Recognition Works
AssemblyAI leverages state-of-the-art deep learning models to convert speech to text and understand audio data:
- The audio file is sent to AssemblyAI's API
- Advanced machine learning models analyze the speech
- Text transcription and metadata like speaker IDs, timestamps, sentiment etc. are returned
- Data is processed securely in the cloud for accuracy and speed
Key models:
- Conformer-2 - Most accurate speech-to-text engine
- Speaker Diarization - Detects speaker changes
- Sentiment Analysis - Detects positive/negative sentiment
- PII Redaction - Redacts sensitive personal data
Features and Benefits
Accurate Speech Transcription
- Convert audio from meetings, calls, podcasts, media to text
- 6.8% improved proper noun accuracy over previous version
- 31.7% improved alphanumeric accuracy
- 12% more robustness to noise
Speaker Detection
- Detect speaker changes with speaker diarization
- Label different speakers in transcription
Sentiment Analysis
- Detect positive, negative and neutral sentiment in speech
- Useful for customer service calls, support tickets etc.
Content Moderation
- PII redaction removes sensitive personal information
- Secure customer data and comply with regulations
And more features like speech summarization, chapter detection etc.
Use Cases and Applications
AssemblyAI powers speech recognition for:
Call Center Automation
- Analyze customer support calls with speech-to-text, sentiment analysis and call summarization
- Surface insights to improve customer experience
Media Analytics
- Auto-transcribe video and audio content at scale
- Detect speakers, sentiment, chapters and objects mentioned
Meeting Transcription
- Get shareable transcripts from meetings and conference calls
- Speaker timestamps and names improve readability
Voicemail and Messaging
- Convert voicemails to text for easier triage and storage
- Analyze audio messages at scale for insights
and more use cases...
Who Is It For
The AssemblyAI API helps developers at:
- AI startups - Launch innovative speech products faster
- Enterprises - Add speech recognition to call centers, media workflows etc.
- Academics - Access leading models for research discoveries
- Transcription services - Scale high-accuracy human-in-the-loop services
Industries served include call centers, media, education, telehealth, customer support and more.
Pricing and Plans
AssemblyAI offers pay-as-you-go pricing, only paying for what you use. Volume discounts available.
| Plan | Price |
|-|-|
| Starter | $0.005 per minute |
| Business | Custom pricing |
| Enterprise | Custom pricing |
Support and Integrations
- 24/7 customer support via email, chat and Discord
- Integrations: Python, Node.js, Java, REST, websockets
- Webhook callbacks for transcription events
- Cloud storage integrations like S3, GCS and Azure
Getting Started
Sign up via the Dashboard to get started for free.
Conclusion
AssemblyAI offers the leading speech recognition API using advanced AI to unlock value from voice data. Integrate accurate transcription, speaker detection and audio analysis into your application today.
Important Links
Last Updated: July 25, 2025