Transcribe a pre-recorded audio file

Overview

This guide walks you through transcribing your first audio file with AssemblyAI. You will learn how to submit an audio file for transcription and retrieve the results using the AssemblyAI API.

When transcribing an audio file, there are three main things you will want to specify:

1. The speech models you would like to use (required).
2. The region you would like to use (optional).
3. Other models you would like to use like Speaker Diarization or PII Redaction (optional).

Prerequisites

Before you begin, make sure you have:

Step 1: Set up your API credentials

First, configure your API endpoint and authentication:

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import assemblyai as aai
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aai.settings.base_url = "https://api.assemblyai.com"
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aai.settings.api_key = "YOUR_API_KEY"

Step 2: Specify your audio source

You can transcribe audio files in two ways:

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audio_file = "https://assembly.ai/wildfires.mp3"

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audio_file = "./example.mp3"

Step 3: Submit the transcription request

Create a request with your audio URL and desired configuration options:

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config = aai.TranscriptionConfig(
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    speech_models=["universal-3-pro", "universal-2"],
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    language_detection=True,
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    speaker_labels=True,
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)
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transcript = aai.Transcriber().transcribe(audio_file, config=config)

This configuration:

• Uses both the universal-3-pro and universal-2 models for broad language coverage. Learn more about our different speech recognition models here.
• Uses our Automatic Language Detection model to detect the dominant language in the spoken audio.
• Uses our Speaker Diarization model to create turn-by-turn utterances.

Step 4: Poll for the transcription result

Transcription happens asynchronously. Poll the API until the transcription is complete:

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if transcript.status == aai.TranscriptStatus.error:
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    raise RuntimeError(f"Transcription failed: {transcript.error}")
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print(f"\nFull Transcript:\n\n{transcript.text}")

Step 5: Access speaker diarization (optional)

If you enabled speaker labels, you can access the speaker-separated utterances:

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for utterance in transcript.utterances:
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    print(f"Speaker {utterance.speaker}: {utterance.text}")

Complete example

Here is the full working code:

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import assemblyai as aai
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aai.settings.base_url = "https://api.assemblyai.com"
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aai.settings.api_key = "YOUR_API_KEY"
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# Use a publicly-accessible URL
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audio_file = "https://assembly.ai/wildfires.mp3"
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# Or use a local file:
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# audio_file = "./example.mp3"
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config = aai.TranscriptionConfig(
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    speech_models=["universal-3-pro", "universal-2"],
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    language_detection=True,
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    speaker_labels=True,
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)
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transcript = aai.Transcriber().transcribe(audio_file, config=config)
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if transcript.status == aai.TranscriptStatus.error:
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    raise RuntimeError(f"Transcription failed: {transcript.error}")
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print(f"\nFull Transcript:\n\n{transcript.text}")
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# Optionally print speaker diarization results
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# for utterance in transcript.utterances:
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#     print(f"Speaker {utterance.speaker}: {utterance.text}")

Next steps

Now that you have transcribed your first audio file:

• Learn how you can do even more with Universal-3-Pro with prompting
• Explore our Speech Understanding features for more ways to analyze your audio data
• Learn more about searching, summarizing, or asking questions on your transcript with our LLM Gateway feature
• Find out how to use webhooks to get notified when your transcripts are ready

For more information, check out the full API reference documentation.