Documentation Index
Fetch the complete documentation index at: https://assemblyai.com/docs/llms.txt
Use this file to discover all available pages before exploring further.
Overview
Universal-3 Pro is our most powerful Voice AI model, designed to capture the “hard stuff” that traditional ASR models struggle with. It delivers state-of-the-art accuracy for entities, rare words, and domain-specific terminology out of the box, with code switching and optional prompting for more control. It’s also our fastest model, so you get the best accuracy without sacrificing speed. Universal-3 Pro is available for both pre-recorded (async) and streaming use cases. Configuration and settings differ between the two because streaming is optimized for real-time audio utterances typically under 10 seconds, with special efficiencies built into the model for low-latency turn detection and voice agent workflows. Based on your use case, navigate to the appropriate guide below:Universal-3 Pro Async
For pre-recorded audio files. Supports long-form audio, prompting, keyterms
prompting, and full language detection.
Universal-3 Pro Streaming
For real-time audio streams. Optimized for low-latency turn detection, voice
agents, and live transcription.