> ## 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.

# Introducing Universal-3.5 Pro

> Learn how to transcribe audio using Universal-3.5 Pro.

## Overview

Universal-3.5 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-3.5 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:

<CardGroup cols={2}>
  <Card title="Universal-3.5 Pro Async" icon="file-audio" href="/pre-recorded-audio/universal-3-5-pro">
    For pre-recorded audio files. Supports long-form audio, prompting, keyterms
    prompting, and full language detection.
  </Card>

  <Card title="Universal-3.5 Pro Streaming" icon="microphone-lines" href="/streaming/getting-started/transcribe-streaming-audio">
    For real-time audio streams. Optimized for low-latency turn detection, voice
    agents, and live transcription.
  </Card>
</CardGroup>