AssemblyAI

AssemblyAI is a developer-focused AI speech and audio intelligence platform, providing transcription, speaker diarization, audio understanding, and LLM-powered audio analysis through a single developer SDK. Founded in 2017 and headquartered in San Francisco, AssemblyAI has raised $158 million in total funding.

Enterprise customers include NASA, Spotify, The Wall Street Journal, NBC Universal, CallRail, and Fireflies. The Universal-1 model delivers best-in-class transcription accuracy with significantly lower hallucination rates than OpenAI Whisper in production environments, making it the preferred choice for compliance-sensitive voice applications.

LeMUR, AssemblyAI's LLM framework, enables developers to ask questions about audio content, generate summaries, and extract structured data directly from transcribed audio without building a separate post-processing pipeline. Audio Intelligence models provide sentiment analysis, speaker diarization, topic detection, content moderation, and auto-chapters from a single API call.

Streaming transcription achieves under 300ms latency with per-word timestamps for real-time applications. The platform supports over 99 languages with automatic language detection.

Pricing starts at $0.65 per hour with per-second billing and volume discounts for enterprise deployments. SOC 2 Type II certified with HIPAA-compatible deployment options for healthcare voice applications.