📊 AssemblyAI by the Numbers
🚀 Developer-First Features
Universal Speech Model
The Universal model delivers 93.3% word accuracy rate with near-human performance, even on noisy or challenging audio. Built for general-purpose transcription across 99 languages.
- • 93.3% word accuracy rate
- • Handles noisy audio
- • 99 language support
Real-Time Streaming
Ultra-low latency streaming via secure WebSocket API returns partial and final transcripts within ~300ms. Perfect for live captioning and voice agents.
- • ~300ms P50 latency
- • WebSocket API
- • Partial & final transcripts
Speaker Diarization
Automatically detect multiple speakers in audio files and identify what each speaker said. Receive utterance lists with speaker labels for meeting transcription.
- • Multi-speaker detection
- • Speaker-labeled utterances
- • Meeting-ready output
LLM Gateway Integration
Single API access to OpenAI GPT, Anthropic Claude, Google Gemini, and more. Build AI-powered features on top of transcripts without managing multiple integrations.
- • OpenAI, Claude, Gemini access
- • Single API endpoint
- • AI-powered transcript analysis
Code-Switching Support
Detect and transcribe conversations that switch between languages mid-speech. Best results for English+Spanish or English+German combinations.
- • Mid-speech language switching
- • English+Spanish optimized
- • English+German support
Multilingual Streaming
Stream multilingual content with the universal-streaming-multilingual model supporting English, Spanish, French, German, Italian, and Portuguese (beta).
- • 6 languages in streaming
- • More languages coming 2026
- • Beta multilingual support
⚖️ AssemblyAI Pros & Cons
✓Strengths
- • Developer experience: Clean APIs, comprehensive SDKs for Python, JavaScript, Go, and more with excellent documentation
- • Affordable pricing: $0.15/hour for Universal model makes it accessible for startups and side projects
- • Real-time streaming: Ultra-low ~300ms latency perfect for voice agents and live applications
- • LLM integration: Built-in gateway to major LLMs simplifies building AI-powered voice features
- • Generous free tier: $50 in free credits to test all features before committing
⚠Limitations
- • No end-user interface - requires coding knowledge to implement and use
- • No meeting bot: Does not automatically join Zoom/Meet/Teams calls like Otter or Fireflies
- • Limited multilingual streaming: Real-time streaming only supports 6 languages currently (more coming 2026)
- • API-only workflow: Every feature requires API calls - no visual dashboard for non-technical users
🎯 Perfect For These Use Cases
Voice AI Applications
Developers building voice agents, virtual assistants, and conversational AI applications needing reliable real-time transcription.
Meeting Software
SaaS companies adding transcription, summaries, and action items to their meeting or collaboration platforms.
Media & Content
Podcast platforms, video editors, and content tools needing accurate transcription with speaker identification.
💰 2025 Pricing Structure
Free Credits
- • $50 free transcription credits
- • Access all API features
- • No credit card required
- • Full SDK access
Universal Model
- • Pre-recorded & streaming
- • 99 language support
- • Speaker diarization
- • Billed per second
Slam-1 Model
- • Pre-recorded only
- • Higher accuracy model
- • Enterprise features
- • Volume discounts available
