OpenAI Speech-to-Text

Overview

OpenAI Speech-to-Text uses the OpenAI Audio Transcriptions API (POST /audio/transcriptions) with Whisper models to transcribe audio files into text. Accepts binary audio input (mp3, mp4, mpeg, mpga, m4a, wav, webm) and returns a transcription in the specified format (json, text, srt, vtt, verbose_json). Supports optional language hints (ISO-639-1), temperature control, and timestamp granularities for verbose output.

Node Type

Action (Binary) — handles file/binary data operations

Input / Output

Direction	Port(s)
Input	Input
Output	Output, Error

Credentials

This tool requires OpenAI credentials. See the Credentials Guide for setup instructions.

Parameters

Parameter	Type	Required	Default	Description
Model	options	No	(current default)	The speech-to-text model to use for transcription. Always uses the latest version (auto-updated). The pre-filled option is the recommended default; the legacy Whisper option is kept for backward compatibility.
				Options: the OpenAI speech-to-text models available to your workspace — pick one from the dropdown.
Binary Property Name	string	No	data	The name of the binary property containing the audio file to transcribe. Names are case-sensitive — see the upstream node’s Binary Data panel for the exact names to use.
Language	string	No	—	Optional ISO-639-1 language code (e.g. “en”, “es”, “fr”) to hint the language of the audio. Improves accuracy when specified. Supports expressions.
Options	collection	No	{}	Optional transcription settings — add only the fields you need.
— Response Format	options	No	json	The format of the transcription output.
				Options: json (simple JSON with a text field), text (plain text), srt (SubRip subtitles), vtt (WebVTT subtitles), verbose_json (segments, words, duration and language)
— Temperature	number	No	0	Sampling temperature (0-1). Higher values make output more random, lower values more deterministic.
— Timestamp Granularities	options	No	—	Timestamp granularity for verbose_json output. Requires response format to be verbose_json.
				Options: empty (no timestamp granularity — the default), word (word-level timestamps), segment (segment-level timestamps)
— Response Field Name	string	No	transcription	The output field name where the transcription text will be stored.
Include Input	boolean	No	false	Whether to include the original input item fields in the output alongside the transcription.
Max Concurrency	number	No	5	Maximum number of items to process concurrently.

Output Data

One output item per input item. The transcript lands on the field named by Response Field Name (transcription by default), with model beside it. The rest of the input item JSON is dropped unless Include Input is on; the input audio binary is forwarded unchanged.

{
  "transcription": "The transcribed text",
  "model": "the transcription model that was used"
}

• With Response Format set to text, srt or vtt, the response field holds the raw string in that format — ready to write straight to a file.
• With verbose_json, four extra fields join the item: segments, words, duration and language. words is only populated when Timestamp Granularities is set to word.

Reference the result downstream by expression, e.g. {{ $json.transcription }}.

Example Configuration

Transcribe audio arriving on the default binary property:

{
  "type": "openai_stt",
  "parameters": {
    "binaryPropertyName": "data"
  }
}

Generate SRT subtitles from an English recording:

{
  "type": "openai_stt",
  "parameters": {
    "binaryPropertyName": "audio",
    "language": "en",
    "options": {
      "responseFormat": "srt",
      "responseFieldName": "subtitles"
    }
  }
}

Get word-level timestamps and keep the original fields:

{
  "type": "openai_stt",
  "parameters": {
    "binaryPropertyName": "data",
    "includeInput": true,
    "options": {
      "responseFormat": "verbose_json",
      "timestampGranularities": "word",
      "temperature": 0
    }
  }
}

Error Handling

Mode	Behavior
stop	Halts workflow on first error
continue	Skips failed items, passes successful ones through
errorPort	Routes failed items to Error output port

Tips

openai_stt transcribes audio files into text using whichever OpenAI transcription model is picked in the Model dropdown, via the Audio Transcriptions API. Use it when a workflow receives recorded speech, voice memos, or audio uploads that need converting into readable or processable text. It outputs a transcription result with recognized text in your chosen format such as json, text, srt, vtt, or verbose_json, plus optional timestamps and language metadata, or an error object on the error channel.